Stuppy Aquaponics Blog

System update: Niles, 2/7/18

Posted by Conor Quinlan on Feb 7, 2018, 2:30:00 PM

Niles

 

Nitrogen (mg/L)

 

 

Date

pH

Total Ammonia

Ammonia

Nitrite

Nitrate

Temp (Fo)

EC (mS)

1/08

6.22 -> 7.00

0

N/A

0

-

71

1.94

1/12

6.8

0

 

0

LAB

68.2

2.03

1/15

6.7

0

 

0

-

68

2.00

1/18

6.5 -> 6.95

0

 

0

-

68

2.08

1/24

6.85

0

 

0

-

71.2

2.07

1/30

7.2

0

 

0

-

70.4

2.15

2/01

7.14

0

 

0

-

73.6

2.22

image showing off the full height of the tomatoes which are all fruiting very well in the media bed.

The full height of the tomatoes which are all fruiting very well in the media bed.

 

Water Quality Overview:

Niles will now have it's pH automatically adjusted to maintain the ideal level of 7.2 on a consistent basis using a sensing unit called the pH Mini. The automatic injector uses a relay module, pH probe and peristaltic pump to input a defined amount of concentrated K2CO3 solution after a specific time interval as the pH drops below 7.0. The pH Mini is the third small scale sensor based unit to be tested as a potential Aqueduct accessory and the first to provide the advantage of water quality control. It has been functioning since 1/26 and is the most comprehensive unit to date.

In the image belowyou can see the unit installed just above the system sump which contains the input line for the concentrated K2CO3 buffer solution. The line has been anchored just below the float bed overflow drain to induce the immediate mixing of buffer and system solutions minimizing nutrient precipitation

controller.jpg 

The monthly supplement regiment will remain identical to last month since lab results indicate the system is maintaining ideal nutrients levels for reproductive growth:  200 g of STP (super triple phosphate) 20 g of Micro Mix, 70 g of Chelated iron and 50 grams of MnSO4

 

The results of the water sample from 1/12 reflect that most nutrients levels have reached an equilibrium:

Parameter

Concentration (ppm) (4/20)

Concentration (ppm) (6/20)

Concentration (8/22)

Conc. (10/27)

Conc, (12/06)

Conc.

(1/12)

E.C.

0.64 mS/cm

0.99

1.04

1.16

1.51

1.66

Ca

36.91

48.53

49.11

44.08

47.35

47.1

Mg

23.5

51.83

54.72

54.8

62.34

69.55

Na

60.39

70.27

87.75

100.47

109.65

109.49

Cl

35.31

56.76

49.39

67.52

73.39

73.15

B

0.17

0.44

0.33

0.5

0.69

0.77

Fe

0

2.65

3.76

7.03

7.98

7.65

Mn

0

0.05

0.01

0.04

0.06

0.06

S

64.36

68.65

76.63

96.8

110.28

117.14

Cu

0.01

0.28

0.19

0.34

0.68

0.71

Zn

0

1.16

1.19

1.74

2.62

2.67

Mo

0.01

0.07

0.2

0.03

0.05

0.04

NO3-N

0.02

31.47 (140 as NO3)

35.97

29.38

51.7

70.42

(313 as NO3)

NH4-N

6.73

0.78

0.9

2.77

0.79

0.13

P

0.9

3.96

0

12.19

28.06

32.02

K

10.77

32.87

12.27

36.15

143.37

142.85

The Sodium accumulation rate has actually decreased for the first time which means Na levels aren’t as significant an issue as previously anticipated. The system hasn’t been drained once since it was reset early April of last year and is therefore no longer a major requirement to keep water quality adequate for crops.

Phosphate and Potassium concentrations are remaining relatively stable. This  means the overall fruiting crop nutrient uptake is nearly identical to what is being supplemented. We can confidently conclude that K2CO3 combined with a simple monthly natural supplementation regiment can replicate ideal water quality conditions with a precision similar to that observed in hydroponic systems, and with less effort

Total Nitrogen content has continued to increase at a steady rate and has reached the optimal concentration given the concentrations of P and K.  The system is right around the ideal N:P:K ratio for maintaining reproductive production while maintaining enough vegetative production to continuously promote further growth.

Low Manganese levels continue to be an issue despite doubling the levels of MnSO4. The solubility is not great at higher pH’s and therefore a chelated Mn compound MUST be utilized when naturally available concentrations are negligible in the source water. These minute concentrations do not appear to be affecting many crops negatively, including all the tomato varieties. The only crop that has been affected is spaghetti squash which still has no problem producing viable fruit.

Another water sample will be collected next week by 2/07

 

Fish Overview:

No changes have occurred in the fish feeding rate since the last post a month ago. 180 grams/day has been enough feed to provide the nitrate needed by all the fruiting crops is the media bed and the strawberries in the NFT channels. Total available nitrogen content has increased 20 mg/L since the previous water quality test. That is nearly 90 mg/L of nitrate which is good for maintaining vegetative structure during reproduction.

 

Crop Overview

Four tomato varieties, two pepper varieties and one large squash continue to grow very well under the powerful LED Plessely light fixtures. Reproductive growth continues to dominate all crops and fruit production is at its peak with regular harvests occurring weekly. The spaghetti squash has nearly finished forming its second fruit which is nearly a foot in length and several lbs (See next image)

media1.jpg

It has taken a while but the Jalapeno (firstimage) and Habanero (second image) varieties are making considerable progress on the formation of viable peppers.  These should be harvestable within the next couple weeks.

 media2.jpgmedia3.jpg

All tomato varieties are still producing flowers and have been harvested twice recently, with a 3rd harvest planned for 2/05. Production is identical to that observed in the hydroponic system and blind taste tests show that tomatoes of the same varieties grown in different systems are indistinguishable from each other.

media4.jpg

Above is an image showing off several varieties of tomatoes that have almost fully ripened.  

Strawberries.jpg

 

 NFT Strawberry Update:

Since the last update the number of flowering strawberry crops has increased to 12 crops. This is well over half and is fairly substantial. Of those crops nine of the flowering individuals are younger runners, while the older individuals only make up three of the flowering strawberry crops. It is becoming apparent that once any variety has flowered once, it is more difficult to flower again. Many of the crops now have ripe strawberries making their first appearances and almost ready for harvest.  

Overall, strawberries are best planted in the early spring allowing vegetative growth to fully form by the time the winter season starts and cool temperatures and/or artificial lighting schedule can induce flowering. Fruits are always best grown in cooler temperatures, and are often better tasting too. After the flowering stops the runners should be utilized and grown in the same manner.

 

Integrated Pest Management (IPM) Update:

Since transplanting several outdoor strawberry crops into the NFT channels connected to Nile the aphid population has begun to explode. Like thrips, aphids are hard to spot in the winter as they will produce deep within the strawberry canopy where it is warmer.

Pyrethrum, neem oil and spinosad were applied to only crops infested with the pests (5-6) but there was little effect. 

Similar to the thrips natural pesticides were simply not enough to remove the majority of populations hidden within the crops. So, for the first time Beneficials are being tested in the system to determine their effectiveness at removing large pest populations as well as observe how well the beneficial remain within the confines of the system grow area over time.

Ladybugs are the best candidate for testing trials as they are well known for their love of consuming aphids. They are also known to eat many other common pests including thrips. Approximately 300-350 ladybugs were released on 2/01 and were observed over a several hour period to find that they not only started feeding on the largest aphid populations immediately but also started mating vigorously. After 24 hours many ladybugs could be easily located among the leaves indicating individuals aren’t moving away from the system.

Strawberries2.jpg

Ladybugs are hardy and can tolerate a range of temperatures. They are better suited for utilization in smaller systems like the Aqueduct when temperatures are lowerso they are less likely to migrate away over time.

Other Crops Affected? Recently after discovering aphids on the strawberries a huge population managed to manifest quickly under portions of the spaghetti squash crop in the media bed. This was of particular concern as the tomato crops are fairly close to the infestation. 

What’s the Next Step? Next is to observe the progress of the ladybugs removal over the course of this next week and determine whether more Beneficial’s are required or additional IPM steps need to be taken. In the unlikely event the ladybugs disperse quickly or can’t hold back the growth rate of the aphid population a different beneficial will be utilized and is the main active ingredient in “BotaniGaurd” which uses predatory fungi to destroy pest eggs and larvae.

Topics: Aquaponics, Insect Control, Niles, Strawberries, Pest Management, Beneficials, Aquaponic Supplements