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Design of my upcoming aquaponics system. Need improvement? Comments welcome.

Discussion in 'General Aquaponics discussion - Aquaponics system ' started by SuperBaby, Nov 15, 2021.

  1. SuperBaby

    SuperBaby New Member

    Nov 15, 2021
    Hat Yai

    postimg. cc/gallery/JXSmXQK (please remove the white space before the "cc".


    1. Water pump is rated 60W at 6,000L/hr. Water pumped back to fish pond at 3,000L/hr. The rest is branched to a cooling tower sitting on top of the sump tank (add oxygen, water cooling, remove odor, more nitrification etc).

    2. Radial flow clarifiers: 700L x 2 units. Water retention time is 28 minutes.

    3. Air pump for MBBR is rated 45W 65L/min.

    4. Air pump for DWC is rated 75W 80L/min (I believe this is too low).

    5. Total DWC grow area is 18 sq.meter. Planting lettuce. No fruity plants.

    6. UV light is rated 13W. Running 3 hours a day. I saw a farm posting an article saying UV would cause iron, manganese and boron to precipitate out of water.

    7. 2 or 3 units Venturi valves are used to oxygenate fish pond water. No compressed air as I have high water-to-fish ration. 1kg of Tilapia requires 16.6L of water. I will start with 30L water per 1kg of fish.

    8. I completely removed the mineralization tank from my original design. My fish-to-vegetable ratio is too high (too many fish and not enough grow area). A mineralization tank might be overkilling.

    9. Fish weight:
      3,000L / 30L per kg fish = 100kg (Black Tilapia)

      4th: 84 fish x 0.60kg per fish = 50.4kg
      3rd: 84 fish x 0.36kg per fish = 30.24kg
      2nd: 84 fish x 0.20kg per fish = 16.8kg
      1st: 84 fish x 0.04kg per fish = 3.36kg (3.5" fry @ approx. US$0.11/fry)

      Total fish weight = 100kg

    10. Fish feed:
      4th: 50.4kg fish x 2% = 1.0kg
      3rd: 30.24kg fish x 3% = 0.91kg
      2nd: 16.8kg fish x 4% = 0.67kg
      1st: 3.36kg fish x 5% =0.17kg

      Total feed = 2.75kg

    11. Ammonia produced: 80 grams of TAN/day based on 2.75kg 30~32% protein fish feed per day.

    12. Require 135L of K1 media based on ammonia calculation. K1 media used: 250L K1 in 500L tank.

      I calculated the ammonia produced based on 2.75kg/day fish feed and double the value. I ended up with 250L of K1 media. I purchased the K1 media from an online store in China at US$0.35/L before shipping fee. If I purchase it online in Thailand, I have to pay about 9 times the price!
    Things I haven't decided (NEED MORE COMMENTS):
    1. I might place some steel or PVC supports below the grow-rafts to raise them 3~4 inches above the water level (instead of floating them). This will create some air space below the rafts for the roots to receive more oxygen. Power cost running the air pump can be reduced.

    2. Net pots will be sitting on diameter 75mm perforated plastic caps with 50mm holes on top (instead of sitting directly on the rafts). The caps have some holes at the sides. The top of the caps is protruded which is good to reduce direct sunlight from reaching the beds through the holes (less algae). This will allow air to flow up/down passing the rafts and improve root health.

    3. I still haven't received the fish pond canvas. The exact height of the fish pond is not sure yet. Once I know exactly how high the fish pond is, I will edit the design and add in a water head drop between the fish pond outflow and radial flow clarifier inflow. Currently, as show in the x-section sketch, the fish pond and clarifiers have the same water level. Is a water head drop of 50mm sufficient? The clarifiers are only 2~3 meters away from the pond.

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