Stuppy Aquaponics Blog

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-)

image of the media bed on 11/1, it is filled with beans and peas.

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. 

images showing the change in fish size from 10/4 to 11/1.images showing the change in fish size from 10/4 to 11/1.

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.

float 1.jpg

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