Growing Spaces

[chohm]

starting an experiment: the idea is to have a sustainable fish population that produces fish with little input other than sun. i have 2400 gal tank: solar fountain pumps to a settling tank and then gravity feeds into biofilter (#2 gravel) filling from bottom and spilling back into tank. overflow from settling tank splashes in for aeration. the pump is running at about 100 gal per hour when in full sun, not at all in shade.

initial fish population is fathead minnows that should spawn with temp above 72. also crayfish as bottom feeders and clean up crew. when minnow population is established will add perch to eat minnows. 1-2 years may see perch of suitable size for eating.

would like to do this without any feed, only the algae growing in the tank feeding the minnows, etc. all species should be theoretically able to spawn in the tank and be self sustaining. pump system is relatively low volume for usual fish farming and may not handle large populations.

anyone with similar interest/experience?

[chohm]

fathead minnows have spawned; the tank is filled with tiny fish. filter is working well and seems to provide enough O2. an interesting fact: plants produce O2 during sunlight hours but consume it in the dark; this places a theoretical limit on algae as a food source since an overgrowth will lead to anaerobic conditions at times (in a system without the typical continuous high volume bubbler). go light on fertilizer

my original idea of having all the input be solar (ie no food added) is impractical. i have been feeding the minnows small amounts of ground catfood

perch will join the system in a month or two and we will see what winter brings