Stuppy Aquaponics Blog

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

Video: Testing your Water

Posted by Scott Moore on Jul 7, 2017 2:30:00 PM

Join Conor Quinlan, Stuppy's Aquaponics Engineer, as he demonstrates how to use the API Water testing kit we include with every Aqueduct unit.

This easy to use kit is fantastic for monitoring the quality of your water and gathering data for use in future experiments and classroom activities.

Testing your water frequently can help identify problems early enough that you can correct them, potentially saving you from disaster events like a fish kill. We recommend testing the Aqueduct at least 3 times a week.

As always, we are happy to answer questions! Comment below, or contact our Aquaponics team by email!

aquaponics@stuppy.com

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Topics: Aquaponics, Water, System Maintenance, Video

System Update: Niles 7/6/17

Posted by Conor Quinlan on Jul 6, 2017 2:30:00 PM

Niles

 

Nitrogen (mg/L)

 

 

 

Date

pH

Total Ammonia

Ammonia

Nitrite

Nitrate

Temp (Fo)

Alkalinity

mg/L

EC (mS)

6/16

7.4

0.25

n/a

0.25

150

81

150

1.17

6/19

7.5

0.25

n/a

0.25

-

81

-

1.20

6/21

7.45

0.25

n/a

0

31.5, 140

81

-

1.28

6/23

7.45

0.25

n/a

0

-

82

140

1.20

6/26

7.35

0.25

n/a

0

same

74.5

-

1.22

6/28

7.3

0.25

n/a

0.25

-

77

-

1.21

6/30

7.25

0.25

n/a

0.25

-

77.5

110

1.17

06/16/17 -> 06/30/17 : Total Hardness: 390 -> 360 -> 350 mg/L CaCO3 equ
Calcium Level: 61 -> 59 -> 56 mg/L    Magnesium level: ~58 -> 52 -> 51 mg/L
P (PO4-) = 22.5 -> 15.5 -> 12 mg/L (4 mg/l as P)

An image of the size difference between the collards grown by the LEDs (right) and Fluorescents (left, smaller). The LED fixtures have the ability to produce fully mature crops 5-7 days earlier than the fluorescent fixtures. Below is a table showing the harvest times for mixed lettuce and collards between LEDs and Fluorescents.

 

LED

Fluorescent

Mixed Lettuce

28 days

33 days

Collard Greens

38 days

45 days

 The numbers above represent harvest times it takes to reach the maximum maturity. In an LED set-up these leafy greens can be harvested a couple days earlier. Overall both Flourescent and LED provide more than sufficient light for optimal growth rates with the LEDs being superior and even outpacing the recommended grow time of 45 days for fully mature collards.

Water Quality Overview

Since the clogging of the system on 6/11 and subsequent death of over half the fish nutrient and pH levels have remained steady. No additions other than 100 grams of chelated iron was added to the system in the last 2 weeks.

 On 6/20 a water sample was submitted to JR peters Lab. As expected nitrate accumulation rates have slowed. Despite the lower waste production nitrate and EC seem to be remaining stable with a recently lab tested value of 140 mg/L NO3 (31.5 mg/L as N), more than enough to support the nitrogen needs of any crop. The lab test also gave us more exact K and PO4 levels which have only been rough estimates at this point; K = 33 mg/L and PO4 = 12 mg/L (or 4 mg/L as P). Although both levels appear to be quite low, especially compared with hydroponics, they have been adequate enough to support the growth of not only the two float beds of collards and mixed lettuce but also an entire media bed filled with various heavier feeding fruiting crops including tomatoes, cucumbers, cantaloupe, squash and peppers.  Boron levels are high and are the likely reason behind the discoloration of the cucumber leaves which is sensitive to Boron. Despite the high levels of Mn added to the system via MOST micro mix, Mn concentration are still far too low at 0.05 mg/l. Deficiencies have appeared, and for this reason, the fertilizer manganese sulfate will be used to increase concentration without affecting Boron or other potentially toxic micros. Below is a table of the full results: 

Parameter

Concentration (ppm) (4/20)

Concentration (ppm) (6/20)

E.C.

0.64 mS/cm

0.99

Ca

36.91

48.53

Mg

23.5

51.83

Na

60.39

70.27

Cl

35.31

56.76

B

0.17

0.44

Fe

0

2.65

Mn

0

0.05

S

64.36

68.65

Cu

0.01

0.28

Zn

0

1.16

Mo

0.01

0.07

NO3-N

0.02

31.47 (140 as NO3)

NH4-N

6.73

0.78

P

0.9

3.96

K

10.77

32.87

Fish Overview

The blue tilapia in the Niles system continue to feed at more than the optimal rate. The feeding rate has increased from 170 grams/day to 210 grams/day and fish size has increased from 125 grams/fish to 175 grams/fish. Using the avg. tilapia weight and the data generated by the graph below it was determined that they should be feeding at 2.19%. This is 0.67% lower than their actual feeding rate at 2.86% body weight which means they are consuming nearly 50 grams more feed than expected. Fish feeding rate is increasing at 0.476 grams/fish/week.

Based on the water quality, lower tilapia populations are actually more optimal for our smaller system.

Crop Overview

All of the leafy greens are growing very well as anticipated. The LED float bed now has Asian leafy greens and the fluorescent float bed will be harvested completely on 7/05. From this point forward staggered production will be utilized to produce leafy greens and lettuce in the float beds. This will maintain a steady nutrient uptake.

In the following images you can see the change in crop size that has occurred over the last two weeks in the media bed.

 

The crops have been growing better than anticipated and even our tomatoes have recovered fully and are showing good growth. There is some leaf curling due to high heat loads in the warehouse which can’t be helped. The zucchini squash, cantaloupe and cucumbers are all producing first small fruits.

LED Testing Trial

The LED and fluorescent trial results are in and listed at the top. Exactly as expected the LEDs produce at slightly faster rates. There was no significant difference in taste between the two grow methods although further testing will need to be done to determine the nutrient content of the tissue itself to see if a difference exists. With the LEDs producing stronger pigmentation it is likely crops grown under it will contain higher levels of various nutrients.  

You can see the remaining collards in the Flourescent Float bed below. 

 

Staggered production has already begun in the LED float bed and the same will be done in the other when the collards are harvest very soon.  

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Topics: Aquaponics, Aqueduct Development, Niles, LED

Video: Dealing with floating media

Posted by Scott Moore on Jun 30, 2017 2:30:00 PM

We're back today with more awesome video content.  Here, our systems engineer Conor Quinlan is offering some helpful tips for dealing with a problem common to all Aquaponics systems, Floating media. 

Often, when you first fill a system with water, the expanded clay will float a few inches off the water. While common, this is an issue that is easily solved. You can watch the video to see how we handle it in our Aqueduct system. 

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Topics: Aquaponics, Water, System Maintenance, Video, Media

Experiments Log 6/28/17

Posted by Conor Quinlan on Jun 29, 2017 2:30:00 PM

This Week we are following up on the ongoing Experiments with beneficial organisms in our systems. To learn more about these experiments, check out our earlier post on the subject!

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Topics: Aquaponics, Insect Control, Aqueduct Development, Experiments

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: Niles 6/20/17

Posted by Conor Quinlan on Jun 23, 2017 2:30:00 PM

Niles

 

Nitrogen (mg/L)

 

 

 

Date

pH

Total Ammonia

Ammonia

Nitrite

Nitrate

Temp (Fo)

Alkalinity

mg/L

EC (mS)

6/02

6.8

0.25

n/a

2

>150

78.5

32.5

1.17

6/05

6.7 -> 7.35

0.25

n/a

2-5

>150

77.6

-

1.20

6/07

7.3

0.25

n/a

1-2

>150

77.1

-

1.28

6/09

7.25

0.25

n/a

2-5

>150

76.3

70

1.20

6/12

7.25

0.25

n/a

2-5

>150

80

-

1.22

6/14

7.3

0.25

n/a

2-5

>150

82

-

1.21

6/16

7.4

0.25

n/a

0.25

150

81

150

1.17

06/02/17 -> 06/16/17 : Total Hardness: 380 -> 400 -> 390 mg/L CaCO3 equ
Calcium Level: 54.4 ->62.4 ->61 mg/L Magnesium level: ~59.5 -> 59.5 ->58 mg/L
P (PO4-) = 10 -> 8-10 -> 22.5 mg/L

Above is an image of the Niles system taken on 6/12. Both float beds are growing very healthy mixed lettuce and collards with the LEDs producing individuals that were slightly larger and more colorful. The mixed lettuce in the further 2/3s of the LED bed had to be harvested 6/16 whereas the lettuce in fluorescent float bed will remain in place until 6/21 or 6/23. The collards will be left in the float beds until they are more mature and have been spaced 16” apart to allow for larger growth. The closer 1/3 of the LED float bed, previous seeded with mixed lettuce, was replace with a new variety of Asian leafy greens.

Water Quality Overview

Since there is more than enough Mg available in the water MgCO3 was replaced with a slightly larger deposit of CaCO3 for the next carbonate addition added on 6/05. For the 950-gallon system more CaCO3, 300 grams, needed to be utilized in order to provide the same amount of carbonate as MgCO3. Calcium carbonate is also significantly less soluble than the other carbonates. For this reason 100 grams of K2CO3 was also added to help raise alkalinity, pH and K+ levels.

Nitrite levels have been consistently higher than previously seen in our basic system even with optimal pH and temperature levels. The reason behind this is the large population of 95 fish being utilized in the system.  Another reason is that the clarifier was getting clogged by large clumps of nitrifying bacteria which was growing too quickly for the system to handle. This was lowering the flow rate and keeping the media bed from siphoning regularly. Without regular siphoning the bacteria may not be receiving enough oxygen to preform adequate nitrification. A larger bristle brush pipe cleaner is the best tool you can use to keep the pipes connecting the fish tank, clarifier and media bed clean. This can be purchased at any major hardware store.

On 6/11, over a weekend, the system clogged due to a screen placed over the clarifier outlet for our Shrimp experiment which clogged with nitrifying bacteria faster than anticipated. More surprising was how fast the fish in the system died after the system became clogged. The bypass valve was opened slightly so the system never overfilled but the flow slowed enough to cause ammonia levels to become lethal. Half the fish died and now only 41-42 remain. If the system stops flowing with a large population of fish it takes <24 hours to cause significant damage. This is discussed in more depth in our experiments post next week. 

This also means the nitrification rate is now significantly slower and the pH is no longer as affected leading to higher pH levels. The alkalinity managed to rise to 150 mg/L due to the transpiration of the lettuce and collards in both float beds. This transpiration is very significant (>5 gallons required per day). Overall, the leafy crops appear to have a very strong basifying effect on the system.

 Fish Overview:

The blue tilapia in system #2 continue to feed at more than the optimal rate even after the clog on 6/11. The fish that survived have recovered fully. They are feeding at a rate far higher than expected at 170 grams/day and each weighs an average of ¼ lbs or 114 grams. Using the avg. tilapia weight they should be feeding at 130 grams/day which means they are consuming 40 grams more feed than expected with a feeding at 3.55% body weight per day rate. This means that the tilapia purchased from the commercial fish farm in NM can consume the anticipated maximum for tilapia of 200 g.

It is safe to say that 100 fish, for even the largest Aqueduct layout (both add-ons included), is over-kill. The accumulation of nutrients was already becoming an issue after just over two months since adding the tilapia. This is proven consistent with our recommendation that 75 Tilapia is the upper limit of the system. The data also indicates that a system can function with as few as 25 individuals. We will be exploring a low density system after our next reset. 

 

Crop Overview

The lettuce and collard varieties in both float beds have shown absolutely no problem growing. Any leafy green or lettuce related variety thrive in the Aqueduct environment.

The newly planted Asian greens, under the LEDs, are showing very interesting pigmentation which should produce a very appealing variety visually.

 

LED Testing Trial

As discussed below the first image at the top of this post the LED grown lettuce and collards are growing slightly larger than all of the same individuals under the fluorescent fixture. This is because the LEDs produce a higher PAR at near 350 umols/m2/s vs the fluorescents which output 280 umols/m2/s. The mixed lettuce in the LED grow bed needed approximately 24 days to reach max maturity (first signs of bolting) after being transplanted whereas the fluorescent grown lettuce needed approximately 30 days. The LEDs consume 40% less energy while taking 20% less time to produce similar mass quantities. Below is an image taken on 6/12 showing the difference in size of crops between the two testing float beds:

Below is another image showing the difference in size and pigmentation between two red romaine lettuce individuals of the same variety from each grow bed on 6/16 when the LED lettuce was harvested. The right individual is from the LED grow bed while the left individual is from the Fluorescent grow bed. The LED grown individual appears to have a better luster and red pigmentation as well as overall larger size.

 To the left are images showing the progress of the mixed lettuce and collards in the fluorescent bed and just the collards in the LED bed taken 6/18.

 

The collards in the LED grow bed have gotten so large that they were partially covering the mixed lettuce before it was harvested. Now they cover the area almost completely

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Topics: Aquaponics, Niles

Video: Assembling the Aqueduct

Posted by Scott Moore on Jun 16, 2017 2:30:00 PM

We hope you enjoyed last week's video providing a brief introduction to the Aqueduct!  This week we are pleased to be releasing additional video content. Our team installed a system for Colonial Gardens in Blue Springs, MO recently, and we were able to capture the event on film. 

This is a long video, but highlights just how easy these systems are to set-up. Just Conor and myself were able to complete the job over the span of two short days! While we are somewhat experienced in setting these up, most people should have no issues putting an Aqueduct together in just a short time. Enjoy!

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Topics: Aquaponics, Aqueduct Development, Video

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

New Aquaponic Experiments: Red Worms, Shrimp and Carnivorous Crops

Posted by Conor Quinlan on Jun 13, 2017 2:30:00 PM

Introduction: A primary advantage of aquaponics is the ability to utilize natural organisms and processes that enable the conversion of ammonia based waste into dissolved nutrients for the crops.  The system is a miniature ecosystem that combines natural phenomenon to enable continuous recycling of the solution which in turn greatly reduces the wasting of resources, such as water or nutrients, while maintaining very high food safety standards.

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Topics: Aquaponics, Aqueduct Development, Fish, Experiments