Fish per gallon

[aquaarche]

what is the normal ratio of fish per gallon of water in the fish tank.

I heard 1 inch of fish for every gallon.

I also heard 1/2 lb of fish per gallon.

So actually how many fish per gallon.

I have 30 gallons of water at any given time in my fish tank so how many fish would be ideal.

I am growing lettuce, tomatoes and sweet peas.

[Ironfish]

Hi Aquaarche,

The max for a system is about 1ld / gal., after that tank oxygen is added (this is a "big business setup). For me, I try to stay at 1/2 ld per gallon. When you get higher a lot more things can go wrong fast.
That said if you have 30 gal. you could have 15 pounds of adult fish or a lot of fingerlings.

Ironfish

[aquaarche]

I currently have only 10 three inch gold fish. I'll get some more then they in no way equal that amount in lbs

[badflash]

There is no number. You need to understand your bio filtration system to know. Fish grow and until you have a mature system where the average size is constant (by volume) you can't know.

[jackalope]

aquaarche, one of your countrymen is here, Joel is his handle

[Celticloud]

Hi, I am new to aquaponics, designing a 500 gallon tank system to start this spring. I figured I could raise 100 tilapia fingerlings in it.

I am getting a wide range of figures tho. According to Edgar Sanchez http://tilapiafarmingathome.com/default.aspx

"My rule of thumb is to allow for a carrying capacity of 2 pounds of biomass (Tilapia) per cubic foot of water.

Lets picture a 500 gallon kiddie pool. It has a volume of 66.85 cubic feet. At a density of 2 pounds per cubic foot we could have in this pool 66 two pound Tilapia, OR 132 one pound Tilapia, OR 264 half pound Tilapia, etc."

He is not doing aquaponics, straight aquaculture, tho. Also I have heard opinions of 1:1 ratio for cubic foot of bed to fish tank.

Best Wishes,
Tom Cloud
Filaree Farm
www.filareefarm.com

[badflash]

I'd stay well clear of Mr. Sanchez. In a mature system with good filtration, one pound per gallon is possible, but has no margin. Go one pound per 2 gallons and be sure to have several bubblers in the tank. Particulate removal and air are the key. You can judge your system by the water quality.

[rfeiller]

7.5gals per cu ft
are you talking about totally closed systems? you rely on the plants obsorbtion of contaminants from the water to maintain the water quality?

[catfish]

Who is Mr. Sanchez and why should I stay clear of him?

[keith_r]

a good rule of thumb in AP is 25lb grown out fish for every 100 gallons of grow media (the filtration) on a mature system
higher densities can be achieved by adding "manual" filtration and air