Stuppy Aquaponics Blog

System Update: Frasier, February/March

Posted by Conor Quinlan on Jul 25, 2018 11:59:07 AM

Frasier

 

Nitrogen (mg/L)

 

 

Date

pH

Total Ammonia

Ammonia

Nitrite

Nitrate

Temp (Fo)

EC (mS)

2/12

6.4 -> 7.0

0

N/A

0

-

73.5

2.1

2/16

7.15

0

 

0

-

76.6

2.2

2/21

7.02

0

 

0

LAB TEST

74

2.3

2/27

6.7

0

 

0

-

67

2.22

3/07

6.35 -> 6.5

0

 

0

-

66

2.4

3/12

6.6 -> 6.8

0

 

0

-

69

2.4

3/21

6.6

0

 

0

-

76

2.7

3/26

6.35 -> 7.1

0

 

0

-

72

2.5

3/28

7.0

0

 

0

-

76.5

2.7

Above is an image of the float bed on 03/21 with leafy lettuce and iceberg lettuce dominating the area. Since the last update on 2/16 these have been our primary crops, along with red and green cabbage. The media bed has been completely cultivated with the heavy feeding greens such as Brussels Sprouts, Broccoli, and Cauliflower to determine if the fluorescent lights can provide the energy necessary to grow a harvest-able product. This was also done to determine the effects on water quality and nutrient absorption over time.

Integrated Pest Management

The Thrip population has not been a problem on either the float or media beds since their population was eradicated previously. The beneficial pesticide Botaniguard ES has been used recently to help kill any young/resistant thrip individuals that might not have been killed by Pyrethrum or Spinosad. 

Water Quality

A variety of Magnesium(Mg), Calcium(Ca), and Potassium(K) based carbonates are being incorporated into the system to measure the buffering capabilities of different mixtures as well as determine other significant influences particular combinations may have on pH and nutrient concentrations. Since K2CO3 has a less significant effect on the system’s buffering capacity on a per mass basis when compared with MgCO3 and CaCO3 it should only be used to give K levels a boost. Also CaCO3 has a very low solubility in neutral water therefore higher levels of MgCO3 are more ideal for optimal pH buffering.

Mg : Ca : K  (Ratio)  =   2 : 1 : 1

(3x) unique carbonate mixtures were required over the last 7 weeks to maintain pH and buffering capacity. Each addition measure a total of 250 grams total/addition.

The same amounts of all other, non-carbonate based, supplements were added again to maintain water quality for the next month. The latest lab sample was collected on 2/21 and indicated stable concentrations of most nutrients since adding the following supplemental compounds to the solution 2/12 and 3/12:

Super Triple Phosphate(STP): 100 grams, Chelated Iron: 75 grams, Micro Mix: 15 grams.

Below are the results of all lab tests conduct on system #1 since before and after the most recent Start-Up including the most recently test taken on 2/21. Another sample was collected 4/02 for analysis, expectations are positive

Parameters:

(Nutrients = ppm or mg/L)

(EC = mS/cm2)

Before RESET (8/22)

After START-UP 10/27

12/06

 

1/12

2/21

E.C.

1.53

0.86

1.16

1.51

2.05

Ca

64

39.06

42.31

48.97

58.62

Mg

79.5

34.19

42.84

56.76

91.23

Na

148.31

73.57

86.19

87.75

118.07

Cl

98.68

47.76

57.83

59.22

77.56

B

0.51

0.32

0.48

0.56

0.63

Fe

6.15

3.53

4.31

3.88

3.43

Mn

0.08

0.03

0.04

0.02

0

S

138.65

67.79

81.11

88.57

120.86

Cu

0.46

0.43

0.59

0.55

0.65

Zn

2.35

0.81

1.22

1.2

1.38

Mo

0.23

0

0

0.03

0.01

NO3-N

29.53

26.98

43

89.85

121.9

NH4

1.18

3.26

0.97

0.24

0.76

PO4-P

10.58

8.6

13.53

16.55

21.11

K

28.34

25.48

97.04

145.4

198.12

There have been no nutrient related incidents or issues and even with the lower levels Mn, heavier feeding crops like the Brussels sprouts and broccoli are growing without showing any signs of significant nutrient related deficiencies.

Positives:

Nitrate (NO3-) – Nitrate has reached levels more than adequate for even the heaviest feeding vegetative crops and signifies that it is time for the fish population to be thinned in order to keep nitrate levels from over accumulating and making crops overly vegetative. Symptoms of high nitrate levels  include dark green, thick, leathery leaves.

Phosphate (PO4-3) – Very important for fruiting crops but is only required in limited amounts for ideal vegetative growth. Unlike K, high PO4 concentrations can actually compete with NO3 for absorption by crops as well as promote them to flower and should be maintained <40 mg/L to maintain more aggressive vegetative growth and 20-40 mg/L for reproductive growth.

Potassium (K+) – Probably the single most important nutrient for all crops as it is required at the highest concentrations compared with any other nutrient. Even for purely vegetative growth, solutions with higher potassium produce better yields. Even more K is required for reproductive growth. K levels have increased significantly since the last test on 1/12 and would normally be considered high for vegetative growth but with the incorporation of the heavy feeders like Brussel sprouts more K can be helpful.  

There were NO significant negative water quality parameters that affected crop of fish growth/health visibly. It should be noted, however, that Mn levels are still very low and Na levels have increased significantly since the last test. Neither of these changes has prompted any negative crop or fish related issues. Mn may just have enough availability to keep crops from exhibiting any deficiency.

Fish Update

The higher temperatures have been persisting the last couple months therefore the fish feeding rate has been able to increase but at a far slower rate than anticipated by our fish feeding calculator. Even so, the results have show the fish have no problem growing to optimal size. Below is an image taken on 3/28:

Each fish weighed about 175 grams/fish on 2/12 and now weighs just over 325 grams/fish (weighed on 3/27), that’s a +150 grams increase in size over 7 weeks. It has been 26 weeks since the fish were only 10 grams each and the fish feed calculator indicates that they are just under their optimal size at only 10-15 grams below the target weight.

The feeding rate is considerable lower than the calculated total/day yet the weight of the fish is still almost as large as anticipated. Feeding rate is only at 350 grams/day, or 150 grams/day less than the calculated total. The fish should also be growing at a slower rate to match the lower feeding rate. This is further proof that feeding rates DO NOT need to be as large as anticipated to induce appropriate fish growth rates. In addition lower feeding rates are far more appropriate for optimal nutrient accumulation over time.  

Crop Update

The media bed is now filled to the brim with about over a dozen huge Brussels Sprouts (3x), Broccoli (5x), and Cauliflower (5x) crops all of which are growing very well. The Brussel Sprouts are just beginning to form there first harvestable leafy greens but whether or not the fluorescent grow lights can produce the amount of PAR necessary to create a viable harvest is unclear.  For this exact reason one of each heavy feeding variety was also transplanted into the LED media bed apart of system #2 in order to observe differences in overall crop growth & development at various light intensities. Below is an image of the media and float beds on 2/21 (top) and 3/21 (bottom).

 

 

 

 

 

 

As of 04/02 it has been just over two month since transplanting the large heavy feeding leafy greens; each is nearly 3 months old now (since first seeded).

All the newly planted crops are growing very well and only a few thrips have been spotted since the crops have matured. The beneficial pesticide BotaniGaurd ES in being used in conjunction with a bi-weekly Spinosad spray to keep any hard to kill larvae and eggs from surviving (uses the predatory fungus Beauveria Bassiana)

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Topics: Aquaponics, System Maintenance, Frasier

System Update: Frasier 1/9/18

Posted by Conor Quinlan on Jan 9, 2018 2:30:00 PM

Frasier

 

Nitrogen (mg/L)

 

 

Date

pH

Total Ammonia

Ammonia

Nitrite

Nitrate

Temp (Fo)

EC (mS)

12/6

6.45 ->7.2

0

N/A

0

190 mg/l

75

1.26

12/13

6.75

0

 

0

-

65, 72

1.38

12/20

5.8 -> 7.02

0.5

 

0

-

66,77

1.52

12/23

6.5 -> 7.2

0

 

0

-

-

1.60

1/02

6.0 -> 7.1

0.5

 

0

-

57, 64.5

1.90

1/05

6.6

0

 

0

NEW Lab Sample

71.5

1.88

Above is what the media bed and float bed looked like before harvesting on 12/20. Both snap peas and beans grow exceptionally well within the Aqueduct’s media bed and are recommended for use in the curriculum. Below is an image of the media bed and float bed with the new seedlings on 1/02 (seeded 12/20). Nutrient accumulation has been allowed to build up during this seedling stage allowing for greater absorption for heavy feeding crops in the near future.

Water Quality

pH fluctuations are allowing for greater additions of the carbonate compound K2CO3, which has increased the concentration of K since the last lab test. The fluctuation has sometimes been extreme bringing the pH to as low as 5.8. This causes an increase in the ammonia concentration as the nitrying bacteria cannot function well at pH’s below 6.5. Between 100-150 gram K2CO3 has been required since the lab test on 12/20 and has been required on a near weekly basis. K2CO3 will need to be replaced by Mg and Ca carbonate based compounds to keep K from competing with cation based nutrient uptake. High K levels potentiate Mn deficiencies, given their similar charge, and have led to slight deficiencies observed in several string beans crops.

Super triple phosphate (STP), Micro Mix, Chelated Iron and MnSO4 have been added this month on 1/02 to speed up the production process. The following amounts of nutrients were added to the system the last month:

STP -> 100 grams, Chelated Iron -> 75 grams, MnSO4 -> 50 grams, Micro Mix -> 15 grams.

The values above have been increased since last month’s addition, notably Mn. These additions have helped increase the EC quickly. Below are the results of the lab sample taken on 12/06:

Parameter

Conc. (ppm)
(8/22)

Conc. (ppm)

10/27

Conc. (ppm)

12/06

E.C.

1.53

0.86

1.16

Ca

64

39.06

42.31

Mg

79.5

34.19

42.84

Na

148.31

73.57

86.19

Cl

98.68

47.76

57.83

B

0.51

0.32

0.48

Fe

6.15

3.53

4.31

Mn

0.08

0.03

0.04

S

138.65

67.79

81.11

Cu

0.46

0.43

0.59

Zn

2.35

0.81

1.22

Mo

0.23

0

0

NO3-N

29.53

26.98

43

NH4

1.18

3.26

0.97

PO4-P

10.58

8.6

13.53

K

28.34

25.48

97.04

The results above show there are several key nutrients that are having an impact on water quality conditions. The negative issues are results of low quality source water and high sodium feed which we currently use to run the system. Our 3.5mm catfish feed has a lower sodium content and has shown to produce lower sodium accumulation over time.

Positives:

Nitrate – As the fingerling have grown in size they have produced a large amount of ammonia based waste which has been converted into nitrate by the nitrifying bacteria in the media bed. This increase has put nitrate level at the lower end of the ideal range for aggressive vegetative growth.

Phosphate – Very important for fruiting crops, phosphate levels don’t need to be nearly as high as nitrate and potassium; in fact, very little P is required for the successful growth of leafy green and vegetative based crops within aquaponics. However, flower development and root growth rate is greatly affected by P concentrations, therefore when root growth is minimal it could be due to very low phosphorous levels.

Potassium – Probably the single most important nutrient for most fruiting crops, potassium is required in the highest concentration by varieties such as tomatoes, cucumbers and peppers. Higher levels of potassium are obtained from the compound K2CO3 which is added to buffer pH as well as add large doses of K. Thanks to the ideal water and air temperatures the pH has consistently decreased over time requiring regular carbonate additions. This will be useful for the growth of heavy feeding cold season crops that will be seeded in the near future, such as Brussel sprouts and cabbage varieties.

Negatives:

Sodium – Sourced from both the tap water and fingerling fish feed. The feed is the primary cause of higher sodium levels over time but decreases when it is changed to the 3.5 mm size catfish feed which is prepared with a lower sodium content. Some few crops, mainly light feeding herbs like oregano and thyme, cannot be seeded at these concentrations. It is recommended to seed crops in a small germination station outside the system with pure water when Na is >100 ppm before transplanting into the system.

Manganese (Mn) – Mn can often be sourced directly from the water being used, nut unfortunately our tap water doesn’t contain sufficient levels of dissolved Mn. While MnSO4 does appear to add some Mn to the solution it is very minimal due to the compounds lower solubility at higher pHs. For this reason, double the amount of MnSO4 (50 grams) was added during the most recent addition.

The higher temperatures during the summer months caused pH to remain consistently high, lowering carbonate addition required. Lower temperatures over the winter, coupled with inline water heating, has led to the appropriate pH response of decreasing overtime. This is due to the water temperature staying within a more ideal range for the nitrifying bacteria. Based on experimentation and observations in the summer and winter it is clear that clogging is far more likely to occur when the water temperature is EITHER higher or lower than the ideal range of between 70-78 F.

A water sample was taken on 1/05 for JR laboratories and will be discussed in the next update.

Fish Update:

The last fish weighing was taken on 12/23 before the holiday break and each fish weighed an average of 100 grams, up 20 grams compared with what they were two weeks before. According to our fish growing schedule the tilapia are slightly above where they should be in terms of size, while being lower in anticipated feeding rate. The fish were fed a max of 145 grams of feed per day before weighing, according to the tilapia grow schedule they should require 180 grams per day at their current size.

Water temps are falling further below the ideal level due to the low air temperatures in the warehouse and therefore the feeding rate had to be further decreased from the max of 156 grams per day, set after weighing, to a minimum of 120 grams per day. Whether this will affect the growth rate of the tilapia will be determined during the next weighing.

Despite the low feeding rate, the fish are of adequate size to switch over to the 3.5mm catfish feed starting next week.  

 

Crop Update:

The entire system has been filled with new cold season crops. The float beds contain both iceberg and green/red cabbage varieties while the media bed contains more string bean and snap pea varieties. This time far more snap peas were seeded as they were found to take up far less space than the beans.

The crops are growing but unfortunately the thrip infestation came back over the holidays and nearly destroyed all the new seedlings. The area was treated with neem oil before seeding but thrips have been known to survive below the surface of media and given the cold air environment I wouldn’t be surprised if the thrips find this preferable, making them even more difficult to kill off. I have switched the natural pesticide to a pyrethrum/sulfur mix which is known for being fairly potent but is proving to be less effective than anticipated. The crops will continue to be sprayed until the infestation is depleted and other crops surrounding the area will be treated with the mix as well to help ensure they do not spread. If the mix doesn’t kill the thrips within the next week or two, a new pesticide will need to be sourced.

Brussel sprouts will be one of the large crops seeded in the media bed next as the cooler temps are ideal for their production. String beans and snap peas will continue to be seeded as well.

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Topics: Aquaponics, Water, Pest Management, Frasier, Aquaponic Supplements, Potassium

System Update: Frasier 12/12/17

Posted by Conor Quinlan on Dec 12, 2017 2:30:00 PM

Frasier

 

Nitrogen (mg/L)

 

 

Date

pH

Total Ammonia

Ammonia

Nitrite

Nitrate

Temp (Fo)

EC (mS)

11/01

6.8

0

N/A

0.5

120

Act. test

63.5

1.00

11/08

6.8

0

 

0

-

63

0.99

11/10

6.94

0

 

0.25

-

73.5

Heater ON

1.07

11/13

6.7->7.1

0

 

0

150

73.5

1.08

11/15

6.91

0

 

0

-

76.6

1.12

11/22

6.45->6.9

0

 

0

-

75

1.22

11/27

6.5->7.1

0

 

0

200

75

1.25

11/30

6.9

0

 

0

-

76

1.30

12/4

6.7

0

 

0

-

75

1.20

12/6

6.45 ->7.2

0

 

0

Awaiting results

75

1.26

10/27:
Calcium Level: 39.06 mg/L            Magnesium level: 34.19 mg/L
Phosphate Level: 8.6 mg/L           Potassium: 25.5 mg/L

Above the top image is of system on 11/1 and the bottom image is the system on 12/06, filled with beans and peas in the media bed and mustards and romaine in the float bed both of which have been harvested toughly. Bean and peas both grow extremely well in aquaponics conditions and require relatively little supplementation.

Water Quality: It has been 3.5 months since the system was reset and nutrient content is now sufficient for heavy fruiting crop production such as tomatoes, cucumbers and peppers. The lower air temperature (b/t 60-70 F) and the consistent water temperature provided by the inline heater have greatly improved overall water quality condition and chemistry. pH fluctuations are far more common allowing far greater additions of the carbonate compound K2CO3 which enables more effective fruit production. Between 100-125 grams of K2CO3 can be added at a time and maintains pH for about a week. STP(100g), Micro Mix(10g), Chelated Iron(50g) and MnSO4(25g) have been added over the past month as well to speed up the production process.  A water sample was sent in to JR labs on 12/11 which was taken on 12/8. The potassium and phosphate levels are expected to increase greatly because of the higher additions of K2CO3 and STP. This will maintain better fruit production throughout the system life cycle and will even allow feeding rates to be lowered creating a more ideal N:P:K ratio for all crops.

The effects on pH appear to be influenced by crop nutrient uptake which is stimulated mainly by the air temperature surrounding the crops. Temperatures between 60-70 F cause the ratio of cations up taken by the root to increase thus resulting the output of more positively charged particles creating the acidic environment we need to add potassium bases carbonate compounds. This illustrates, from an experimental perspective, how significant and vital it is to maintain ideal crop parameters when utilizing aquaponic or hydroponic growing procedures. The higher temperatures observed during the summer months caused pH to remain higher lowering carbonate addition. Clogging was also more likely to occur for reasons currently not well understood.

 

Fish Update: The high grade tilapias have grown substantially over the past month and were weighed on 12/06 to determine an average weight of 80 grams/fish, an increase of 45 grams per fish since the last weighing on 11/08. This brings the feeding rate up to 170 grams/day at a 3% body weight fed. According to our fish growing schedule we are about 10 weeks into the grow cycle and the tilapia are exactly where they should be in terms of size and a little further along in feeding rate which should be at 160 g/day. These tilapias have had no problem keeping up with growing requirements even when water temperature dropped well below the optimal for several days.

The 2.5 mm feed continues to be used and will be switched once the fish are 14 weeks old.  

 

Crop Update: The system is full of crops now with the float bed supporting various mustard greens and romaine lettuce and the media bed utilizing lighter feeding fruiting crops including beans and peas which are fully mature and have produced several pounds of fruit. Squash have also been placed in the media bed to determine if the nutrient concentration is sufficient enough to support heavier feeding crops at the front of the system. Thus far the vegetative production is perfect but the PAR is not high enough to support fruit development. Crops were allowed to grow to substantial size to show off the growing power of the system and can be seen in our images. 

The romaine and mustards in the float bed were all harvested on 12/06 and will be replaced in a staggered manner by iceberg lettuce and green and red cabbage varieties in the month to come.

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Topics: Aquaponics, Leafy Greens, Frasier, Aquaponic Supplements

System Update: Frasier 11/8/17

Posted by Conor Quinlan on Nov 8, 2017 1:55:49 PM

Frasier

 

Nitrogen (mg/L)

 

 

 

Date

pH

Total Ammonia

Ammonia

Nitrite

Nitrate

Temp (Fo)

Alkalinity

mg/L

EC (mS)

10/4

7.21

0

 

0

100-120

77.2

-

0.8

10/6

7.14

0

 

0

-

75.5

-

0.79

10/9

7.02

0

 

0

100-120

74

-

0.85

10/11

6.98

0

 

0

-

-

-

0.83

10/15

6.76

0

 

0

-

-

-

0.85

10/17

6.68

0

 

0

150

67.6

-

0.85

10/19

6.7 -> 7.3

0

 

0

-

68.9

-

0.85

11/1

6.8 -> 6.8

0

 

0.5

150

(act. 120)

63.5

16.5

1.00

10/4 -> 10/10 -> 10/17: Total Hardness: 230 -> 260 -> 260  mg/L CaCO3 equ
Calcium Level: 35 -> 40 -> 40 mg/L            Magnesium level: 34 -> 39 -> 39 mg/L
Phosphate Level: ~ 5-10 -> 10 -> 7  (as PO4-)

The media bed on 11/1, it is filled with beans and peas.

Water Quality

It has been over 2 months since the system was reset.  Nitrate levels are already more than adequate for full production of crops. The lower temperature appears to have improved water quality, although the exact mechanism behind that is not well understood. It has enabled faster pH drops which has required regular additions of the carbonate compound K2CO3. We have also added STP, Micro Mix, Chelated Iron and MnSO4 over the past month.

K2CO3 -> 150 grams; STP -> 150 grams, Chelated Iron -> 50 grams, MnSO4 -> 25 grams, Micro Mx -> 35 grams.

Below is a chart showing the water quality test data from JR labs. The results from 8/22 are the final test before we reset the system.

Parameter

Conc. (ppm)
(8/22)

Conc. (ppm)

10/27

E.C.

1.53

0.86

Ca

64

39.06

Mg

79.5

34.19

Na

148.31

73.57

Cl

98.68

47.76

B

0.51

0.32

Fe

6.15

3.53

Mn

0.08

0.03

S

138.65

67.79

Cu

0.46

0.43

Zn

2.35

0.81

Mo

0.23

0

NO3-N

29.53

26.98

NH4

1.18

3.26

P

10.58

8.6

K

28.34

25.48

Concentrations of every nutrient besides Mo are sufficient enough to produce just about any crop. This is the advantage of starting with the max number of recommended fish. However nutrients will begin accumulating and the fish will need to be thinned to maintain optimal water quality conditions.

 

Fish Update

The high grade tilapias have grown substantially since being introduced to the system. They were weighed on 11/07 to determine an average weight of 34.6 grams/fish, an increase of 23.3 grams per fish since the last weighing on 9/27. This brings the feeding rate up to 103.8 grams/day at a 4% body weigh fed. According to our fish growing schedule we are 6 weeks into the grow cycle and the tilapia are exactly where they should be in terms of both size and feeding rate. The recommended feeding rate is 97.5 g/day at this point which is only slightly below our actual rate.

Some waste is floating at this point; it is possible that the clarifier needs to be adjusted to allow more room at the bottom of the tank for waste settling. This can be accomplished by removing a couple inches from the bottom of the 4” PVC pipe that pushes the waste water down to the bottom of the clarifier. 

Visually it is easy to tell that the tilapias are significantly larger at this point.

 

Crop Update

The system is fully loaded with crops now. The float bed is supporting various leafy greens and lettuces and the media bed utilizing lighter feeding fruiting crops including beans and peas. Squash have also been placed in the media bed to determine if the nutrient concentration is sufficient enough to support heavier feeding crops at the front of the system. Below is an image of the float bed.

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Topics: Aquaponics, Leafy Greens, Water, Experiments, Frasier

System Update: Frasier 10/9/17

Posted by Conor Quinlan on Oct 9, 2017 1:00:00 PM

Frasier

 

Nitrogen (mg/L)

 

 

 

Date

pH

Total Ammonia

Ammonia

Nitrite

Nitrate

Temp (Fo)

Alkalinity

mg/L

EC (mS)

9/6

7.5

0

 

0

30-70

75

60

0.7

9/13

7.45

0

 

0

-

76

-

0.7

9/15

7.45

0

 

0

40-50

77.5

-

0.7

9/18

7.5

0

 

0

80

76.5

60

0.74

9/20

7.5

0

 

0

-

79

-

0.72

9/22

7.43

0

 

0

-

81

-

0.72

9/25

7.22

0

 

0

80

80

50

0.77

10/4

7.21

0

 

0

100-120

77.2

 

0.8

8/30 -> 9/18 -> 9/25 -> 10/4: Total Hardness: 200 -> 210 -> 230 -> 230  mg/L CaCO3 equ
Calcium Level: 32-> 40 ->34 -> 35 mg/L   Magnesium level: 30 -> 26 -> 35 -> 34 mg/L
Phosphate Level: ~ 0 mg/L -> 2-5 -> 5-10 (as PO4-)

Water Quality

Water quality is maintaining as expected at this early point in the systems cycle. Nitrate has risev over the past month and pH is slowly decreasing to optimal levels. Nitrate levels are now high enough to bring the system to crop capacity with light to medium feeding crops.

 

Fish Update

The high grade tilapia have grown substantially over the past month. We weighed them on 9/26 to determine an average weight of 11.3 grams per fish. This has brought the feeding rate up to 34 grams/day at feeding 4% body weight. This means the tilapia have grown 7.44 grams since the last weighing on 8/29 and the feeding rate has increased from 14.5 grams/day to 34 grams/day. Unlike our previous trial these commercial grade tilapias are growing much faster than the tilapia obtained from a local fish farm.

Thus far waste from the fingerlings is settling perfectly in the clarifier. This is a sign that the fish are fully digesting the feed as expected.

The quick increase in nitrate accumulation that has occurred since the system was reset indicates that the system has the ability to grow more crops at a faster rate than currently indicated by the curriculum. 75 fish are the maximum number fish that should be added to the system at any one time. Less fish are recommended for systems utilizing a less rigorous growing strategy.

You can see the change in fish size over the past month in the images below. 

Visually it is easy to tell that the tilapias are significantly larger.

 

Crop Update

The float bed has been full of leafy greens since early September, only a week after the system was reset and new fish added. Nitrate levels are now more than significant enough to seed lighter feeding fruiting crops in the media bed. Basil and other heavier feeding leafy greens can also be grown at this stage.  Peas and string beans along with some rooting crops including radishes, beets and carrots were added to the media bed on 10/6 and are doing well. 

The float bed is full of crops now and the lettuce will be replaced with the heavier feeding crop basil.

The media bed has also been seeded directly with peas and beans which should sprout very soon.

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Topics: Aquaponics, Fish, Frasier

System Update: Frasier 9-14-17

Posted by Conor Quinlan on Sep 14, 2017 3:34:07 PM

Frasier

 

Nitrogen (mg/L)

 

 

 

Date

pH

Total Ammonia

Ammonia

Nitrite

Nitrate

Temp (Fo)

Alkalinity

mg/L

EC (mS)

8/22

RESET

 

 

 

 

 

 

 

8/23

7.8

0.5

 

0.5

0

76

-

0.65

8/25

7.75

0.5

 

0.25

10

76

-

0.62

8/28

7.78

0.25

 

0

40

77

-

0.69

8/30

7.7

0

 

0

-

76

-

0.66

9/6

7.5

0

 

0

50-70

76

60

0.7

8/30: Total Hardness: 200 mg/L CaCO3 equ
Calcium Level: 32 mg/L  Magnesium level: 30 mg/L
Phosphate Level: ~ 0mg/L (as PO4-)

Water Quality

Below are the results from the 8/10 water quality test which was sampled just before re-setting the system so these can be considered final results. There are some major differences since the previous test on 6/20. The largest is the decrease in both Nitrate and Potassium. The decrease in potassium is due to lack of addition of K2CO3 over the last couple of months as pH remained high.  This is due to the production of higher feeding crops. The decrease in nitrate concentration is also due to the increased feeding rate of heavier feeding crops like tomatoes, cucumbers, peppers and melons all added around 6/20. Nitrate concentration was highest on 6/20. This was due to the switching of light feeding fruiting crops like beans and peas to heavier feeding fruiting crops allowing nitrate accumulation to occur.  

Sodium and sulfur levels are continuing to rise substantially. Our conclusion is that the compound are not reaching a plateau. It is these compounds that have maintained EC while nitrate and K levels have dropped over time.

Other nutrient levels are appropriate, particularly the micronutrients. Only Mn continues to maintain very low concentrations but it has remained high enough to keep any deficiencies from occurring thanks to the Micro-mix and MnSO4.

Overall despite lower nitrate and K the growth rate and quality of the crops within the system seemed unperturbed. The Asian eggplant in particular was producing many fruit at an aggressive rate and no crops developed any significant deficiencies other than micro (Fe, Mn) based. 

Parameter

Conc. (ppm)
(8/22)

Concentrations (ppm) (6/20)

Concentration (ppm) (4/20)

Previous Data from (2/20)

E.C.

1.53

1.49

1.17 mS/cm

0.95

Ca

64

63.19

56.49

40.2

Mg

79.5

75.18

48.53

24.6

Na

148.31

125.58

110.38

86.0

Cl

98.68

108.75

85.64

70.4

B

0.51

0.4

0.23

0.14

Fe

6.15

6.88

2.91

1.97

Mn

0.08

0.09

0

0.003

S

138.65

106.63 (300 as SO4)

88.03 (250 as SO4)

188 (as SO4)

Cu

0.46

0.25

0.2

0.131

Zn

2.35

1.43

0.62

0.396

Mo

0.23

0.06

0

-

NO3-N

29.53

64.96

47.2

19.7

NH4

1.18

0.81

1

-

P

10.58

7.5

5.83

1.26

K

28.34

46.67

14.7

16.3

 

Fish Overview

Below is a chart showing the appropriate size of tilapia over time. The tilapia from the previous growth period had trouble maintaining appropriate size during their early growth stages due to their lower quality. By week 6 the fish were still <30 g/fish (shown in red)

After reaching close to 50 grams/fish the growth rate increased. So overall it took approximately 16 weeks instead of the recommended 14 weeks to grow the fish out from 10 to 125 grams (shown in orange).

After this point the fish had no problem maintaining the appropriate growth rate and reached the correct size by week 20 (shown in green).

Week #

Increment increase in feed rate (g)

Fish Size (g)

1

 

10

2

0.1

 

3

0.1

 

4

0.2

 

5

0.2

 

6

0.3

<30

7

0.2

50

8

0.2

 

9

0.2

 

10

0.2

 

11

0.2

 

12

0.2

 

13

0.2

100

14

0.2

 

15

0.3

 

16

0.3

125

17

0.3

 

18

0.3

 

19

0.4

200

20

0.4

225

21

0.4

 

22

0.4

 

23

0.4

 

24

0.4

300

 

Below shows the change in size of the fingerlings over the past several weeks. The greatest change is in the fry’s color which has begun to darken as they slowly mature.

The fingerlings were weighed on 8/31 and average just under 4 grams each. This makes the feeding rate 11.6 grams/day at 4% body weight but was quickly increased to 14.5 g/day as the frys continued feeding.

Crop Update

Crops were added almost immediately to the system on 8/29 as nitrate accumulation has already begun just days after system re-set. Mixed lettuce and Asian leafy greens have been added thus far in a staggered fashion. More crops will be added to the system in the near future including light feeding fruiting crops to the media bed. Below is an image of the seedlings so far.

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Topics: Aquaponics, Water, Fish, Frasier

System Update: Frasier 7/11/17

Posted by Conor Quinlan on Jul 11, 2017 3:25:55 PM

Frasier

 

Nitrogen (mg/L)

 

 

 

Date

pH

Total Ammonia

Ammonia

Nitrite

Nitrate

Temp (Fo)

Alkalinity

mg/L

EC (mS)

6/23

7.2

0.25

n/a

0.25

300

82

75

1.67

6/26

7.1

0.25

 

0.25

-

76

-

1.61

6/28

6.85

0.25

 

2-5

-

78

-

1.60

6/30

7.00

0.25

 

0.5

290, 65 (as N)

78

70-80

1.66

7/03

6.95

0.5

 

2-5

-

80.5

-

1.68

7/05

7.00

0.25

 

0.5

-

79

-

1.65

06/23 -> 6/30 -> 7/07:  Total Hardness: 510 -> 470 -> 470-500 mg/L CaCO3 equ
Calcium Level: 65 -> 64 -> 60 mg/L            Magnesium level: 90 -> 83 -> 85 mg/L
Phosphate Level: ~ 25 -> 22.5 -> 20   mg/L (as PO4-)

 

Water Quality Overview: The pH is dropping more consistently than the previous two weeks. This is due to the removal of the collards that were being grown in a batched fashion. The collards have a high nitrate uptake and were causing the water to remain very basic.

On 6/20 we ran new lab water tests and just got our results back. You can see the results compared with the previous tests in the table below. Manganese Sulfate is being used to supplement Mn which is still considerably low (0.09 mg/L) despite the concentration available in the MOST micro mix, 10 grams was added. Just like the Niles system the MOST mix caused Frasier to accumulate boron and copper. This can cause crop toxicity symptoms in sensitive crops. Na concentrations are lower than anticipated and may be reaching a peak, further testing in the future will determine if this is true. Cl levels are rising fairly rapidly still and may continue to accumulate causing slight crop related issues. Sulfate levels appear to be reaching a peak as the nutrient solution has gotten harder over time (near 500 mg/L as CaCO3) which was expected. K levels have increased significantly thanks to the addition of K2CO3 and are now at more than adequate levels to support even the heaviest feeding crops.

Parameter

Concentrations (ppm) (6/20)

Concentration (ppm) (4/20)

Previous Data from (2/20)

E.C.

1.49

1.17 mS/cm

0.95

Ca

63.19

56.49

40.2

Mg

75.18

48.53

24.6

Na

125.58

110.38

86.0

Cl

108.75

85.64

70.4

B

0.4

0.23

0.14

Fe

6.88

2.91

1.97

Mn

0.09

0

0.003

S

106.63 (300 as SO4)

88.03 (250 as SO4)

188 (as SO4)

Cu

0.25

0.2

0.131

Zn

1.43

0.62

0.396

Mo

0.06

0

-

NO3-N

64.96

47.2

19.7

NH4

0.81

1

-

P

7.5

5.83

1.26

K

46.67

14.7

16.3

Fish Update: Fish feeding rate and growth is fairly strong with a near 25 gram/day increase in in the last two weeks. The fish were not be weighed this week due to the 4th of July holiday.

You can see the change that has occurred in size from 5/26 to 7/07 in the images here.  One thing to note is that Frasier has a few fish that are much larger than the others. 

 

  Crop Update: Below is a representation of the crops in Frasier’s media bed. All crops are growing well at this point. The only observable issue is that some of the tomato flowers closer to the fluorescent fixtures are unable to produce pollen due to the high heat and lower humidity. Flowers found closer to the surface of the media bed, away from the fixtures, are producing fruit verifying that the heat from the fixtures is causing the problem.

Below are images of the media bed over time. The first image is from 6/26 and the second is from 7/07. As you can see crop growth has exploded over the last two weeks.

The tomato crops are now beginning to fruit and we will hopefully be having our first tomatoes of the year very soon.

Thrips continue to come back every week or so and are easily kept in check using the natural pesticide pyrethrum.

The strawberries fruit trusses have been clipped since the quality of the fruit is beginning to decline. We are now waiting for the next blossom initiation. To the left is an image showing the change in size of the crops from 6/09 to 7/07. Another row has been removed and the crops are in a vegetative state until temperatures decrease to 50 F at night.

 

 

The beets are getting close to being done and the wet paper towels around the roots continue to do their job, keeping the beets from cracking. Paper towels are replaced every week.

The swiss chard and a few basil crops added more recently to the system on 6/9 are growing very well as expected.

Below you can see the change in crop size in the float bed from 6/26 to 7/07. As you can see, there has been a significant amount of growth in just the past 11 days. 

The basil and chard are doing very well and suffering a very minor Mn deficiency but no other issues. 

 

 


Outdoor Update:
Despite high winds the fruiting crops added to the outdoor grow bed have manifested very well. A couple tomato varieties as well as one cucumber and one cantaloupe are growing outdoors currently. More varieties will be added when the hydroponic NFT system is built for a direct three way comparison between aquaponics, hydro and outdoor grown crops.

 

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Topics: Aquaponics, Fish, Frasier

System Update: Frasier 6/27/17

Posted by Conor Quinlan on Jun 27, 2017 3:26:08 PM

Frasier

 

Nitrogen (mg/L)

 

 

 

Date

pH

Total Ammonia

Ammonia

Nitrite

Nitrate

Temp (Fo)

Alkalinity

mg/L

EC (mS)

6/09

7.00

0.25

n/a

0.25

350

76

50

1.60

6/12

6.9

0.25

n/a

2-5

-

80

-

1.66

6/14

6.85

0.25

n/a

0.5

-

81

-

1.70

6/16

7.05

0.25

n/a

1

300-350

81

57.5

1.62

6/19

 

0.25

n/a

2-5

-

81

-

1.64

6/21

7.15

0.25

n/a

2-5

-

82

-

1.66

6/23

7.2

0.25

n/a

0.25

300-350

82

75

1.67

06/09 -> 06/16 -> 06/23 Total Hardness: 500 -> 520 -> 540 mg/L CaCO3 equ
Calcium Level: 68 -> 67 -> 65 mg/L            Magnesium level: 82 -> 85 -> 92 mg/L
Phosphate Level: ~ 30 -> 25 -> 25   mg/L (as PO4-)

Water Quality Overview:

The pH has been increasing rather than dropping lately. There are a couple of reasons behind this. First is that the source water has a much higher alkalinity than previously observed at 100 mg/L versus 55 mg/L. The change in source water quality is affecting the chemistry of the water,  leading to higher pH levels. This means that our carbonate additions will need to be lowered. It is not unusual for source water quality to change over time and should therefore be measured consistently. The system also has a significant number of larger crops that can easily influence the pH of the solution by taking up more water or releasing higher levels of OH- or H+. The efficiency of the nitrifying bacteria within the media bed is equally as important, a static media bed (no siphoning) can lead to less nitrification and therefore higher pH levels. That was a major part in what occured in our system. 

A clog in the clarifier assembly due to buildup caused the siphon in our system to stop functioning and decreased nitrification production leading to higher nitrite levels. Clearing the clog with a large bristle brush pipe cleaner is very effective and should be done once a week.

The only addition made in the last two weeks was 50 grams of chelated iron which is now required in higher intervals with the addition of the heavier feeding crops in the media bed. It has only been 2.5 weeks (versus 2 months previously) since the last addition signifying how much more rapidly it is being absorbed by the crops.

The only supplements to the solution, besides fish feed, are the three carbonate compounds (K2CO3 MgCO3, CaCO3), JR Peters M.O.S.T Micro mix, Chelated DTPA Iron and Super Triple Phosphate. This is the max number of supplements that can be used in the Aqueduct for the growth of larger fruiting crops such as tomatoes, cucumbers, peppers, melons, strawberries, squash, ect.

 

Fish Update:

Fish feeding rate and growth is fairly strong. The feeding rate has increased to 276 grams/day up from 250 grams/day. The growth of the fish is going well with an increase in size from 125 grams to 228 grams in the past 4 weeks. Using the fish size to feeding relationship the ideal feeding rate should be around 286 g/day so the tilapia are only about 10 grams/day off of their max feeding rate which is very good.

 

Above you can see the change that has occurred in size from 6/09 to 6/26. The second image being the most recent. The fish are growing faster now that the feeding rate is more consistent.

Crop Update:

Below is a representation of the crops in Frasier’s media bed from 6/09 (first) to 6/23 (second). Thus far the only crop having trouble is the cantaloupe.  This is because of its sensitivity to boron,  copper,  or transplanting. The cantaloupe seems to be recovering in the last several days and are growing far more effectively. It is most likely that the reason behind the problem was the stress induced by transplanting the crop.

The tomatoes and cantaloupe are growing very fast.  Their stems are quite thin due to low light levels and are beginning to fall over. Sticks will be needed to hoist them up. A couple of the tomato crops are now beginning to bloom and we will have our first tomatoes of the year very soon.

The thrip infestation is gone.  I have occasionally found a few thrips, so the crops are being tended weekly with natural pesticides until the population is completely exhausted. The crops have recovered from most of the thrip damage.

The strawberries have been trimmed and one more NFT channel has been removed to make more room for the remaining crops.

The strawberries are still very vegetative and consistently put out runners which means flowering is not being triggered. This is due to the high temperatures in our warehouse. A temperature around or below 50 F is generally required for a couple hours at night to induce flowering. Either a solution must be found to cool the strawberries or we are going to have to wait for the fall to get additional strawberry fruits. 

The Swish chard and basil crops which were added to the float bed on 6/09 and are doing well as expected. The basil started growing far better when transplanted from the hydro solution in the propagation tray to the float bed.

Above is an image of the full float bed which now has beets, swiss chard, basil, and a couple radish crops growing.

Below is an image of the beets on 6/09 (left) and (6/26) right. The right image also shows a close up of the towels and how they were wrapped around the beets. The beets are growing far better with moist paper towels wrapped around them. One was left without a towel as a control to observe the difference, which can be observed in the images. 

 

Outdoor Update:

The newly transplanted crops outdoors had some trouble with heavy winds but appear to be recovering nicely. The pepper crop didn’t make it, so it will be replaced. Below are images of the crops (top are the strawberries, bottom are tomatoes, Brussel sprouts, cantaloupe, and squash.

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Topics: Aquaponics, Strawberries, Pest Management, Frasier

System Update: Frasier 6/15/17

Posted by Conor Quinlan on Jun 15, 2017 2:30:00 PM

Frasier

 

Nitrogen (mg/L)

 

 

 

Date

pH

Total Ammonia

Ammonia

Nitrite

Nitrate

Temp (Fo)

Alkalinity

mg/L

EC (mS)

5/26

6.6 -> 7.3

0.25

n/a

0

350

75.5

25 -> 65

1.50

5/31

7.15

0.25

n/a

0

-

76

-

1.54

6/02

7.25

0.25

n/a

0

350

76.5

80

1.60

6/05

7.05

0.25

n/a

0

-

77

-

1.64

6/07

7.15

0.25

n/a

0.25

-

76

-

1.56

6/09

7.00

0.25

n/a

0.25

350

76

50

1.60

05/26 -> 06/02 -> 06/9/17 Total Hardness: 480 -> 510 -> 500 mg/L CaCO3 equ
Calcium Level: 74 -> 68 -> 68 mg/L            Magnesium level: ~72 -> 83 -> 82 mg/L
Phosphate Level: ~ 35 -> 30 -> 25  mg/L (as PO4-)

Water Quality Overview: The 100g K2CO3 and 125g MgCO3 addition continued to maintain the pH above 7.0 for two full weeks. The alkalinity is also increasing to levels higher than have previously been observed with just CaCO3 and MgCO3 due to the higher addition of K2CO3 which dissolves fully in water regardless of Ph.

Other than the typical carbonate addition, 50 grams of chelated iron (equ to 2 mg/L Fe) was added on 6/09 to replenish levels. The last 50 gram addition was added on 4/28 so that addition lasted just over 2 months.

Nitrate levels are more than sufficient for the growth of any crop and enough K has been added over the course of the last couple months to support the growth of any heavy feeding fruiting crop.

The only supplements to the solution, besides fish feed, are the three carbonate compounds (K2CO3 MgCO3, CaCO3), JR Peters M.O.S.T Micro mix, Chelated DTPA Iron and Super Triple Phosphate. This is the max number of supplements that can be used in the Aqueduct for the growth of larger fruiting crops such as tomatoes, cucumbers, peppers, melons, strawberries, squash, ect.

Fish Update: The fish are performing well now that they are larger in size. The feeding rate is now increasing as predicted and has increased from 204 g/day to 252 g/day over the past weeks for a total increase of 0.4g of feed/fish/week. Using this data, we can assume that the fish are around 200 grams in weight which is a significant increase from 125 grams. The fish will be weighed next week to determine their progress since the last weighing on 5/23.

Crop Update: Additional heavy feeding crops have been added to the media bed including more tomatoes, cucumbers, squash, Asian eggplant, and habanero pepper. Pictured below is a drawing showing the placement of the crops paired with a picture of the media bed right now. 

The indeterminate tomato added to the system is growing without a problem with no signs of deficiencies at all. The new crops added to the media bed are expected to perform just as well.

The only hitch is that some of the recently added seedlings have been stunted by the sudden thrip population explosion. Luckily the infestation has been reduced to nearly nothing with the use of a new organic natural pesticide called pyrethrum. When incorporating IPM it is extremely important to rotate natural pesticides regularly to prevent tolerance. For the past year we have been utilizing spinosad, sesame seed oil and insecticidal soap which have become useless against thrips; we are now incorporating pyrethrum, neem oil and diatomaceous earth to control pest population. Since the first application of pyrethrum on 6/02 the thrip population has been reduced to near harmless levels. Crops will be observed on a daily basis to ensure the thrips don’t return to problematic levels. These organic pesticides can be found at local home improvement stores like Home Depot and Lowes.

The strawberries fruit trusses have been clipped since the quality of the fruit is beginning to decline. We are now waiting for the next blossom initiation. In the images below you can see the dramatic change in crop size in the past month. 

 Another row will be removed from the NFT component soon as the strawberries are taking up more and more space.

The radishes were harvested last week, showing significant cracking. This was due to the low humidity of the surrounding air (see image below). The beets are showing similar symptoms and in order to control it moist paper towels have been wrapped around the fruits to keep them wet (see image below). The crops can easily be grown via aquaponics but should be placed in the media bed for adequate humidity and moisture levels around the roots.

 

Outdoor Update: A variety of tomatoes, cucumbers and peppers have been transplanted outside to provide a comparison with our aquaponics grown crops.  Below is an image of the strawberries planted outside. With the increasing summer heat, the strawberries may need to be covered with a shade cloth.

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Topics: Aquaponics, Insect Control, Pest Management, Frasier