Stuppy Aquaponics Blog

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. 

Fish 1.jpgFish 2.jpg

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. 

Float bed 1.jpgFloat bed 2.jpg

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.

Topics: Aquaponics, Fish, Frasier