Both catfish and tilapia are considered omnivorous- they'll eat both animals and plants (some other species, such as trout, are purely carnivorous). Part of my plan is duckweed. The other part of the plan for feeding my fish and closing the loop with humans so far involves worms and bees.
I'm estimating no more than 1 worm per fish per day (depending on fish maturity of course). I don't have an accurate rate for worm propagation in my farm, but guess it is currently well below 40/day (I started with ~600). We most certainly generate enough food byproduct waste to support a larger worm farm. I currently have another non-worm compost tumbler where the bulk of our citrus, yard waste, and food scraps go. I've had this going since last winter and have harvested incrementally from it in the course of planting my garden and fruit trees.
A typical bee hive population fluctuates, peaking around 20,000 in the summer and dropping down to 2000 or less in the winter. Many individual workers are lost to predation (a mechanism likely to be lost in a simplified CELSS), but many just die in the hive toward the end of summer and through the fall. I've designed my hive with a hinged bottom for collecting dead bees, which I will seasonally provide to feed my fish. Once I have both, that is.
Worms and compost
Red wriggler worms are a well established component of aquaponics, traditionally used in the grow bed to help break down solid wastes (primarily fish poop and decayed root matter). While I will likely incorporate them in this manner as well, I have also started a stackable bin worm farm to help with our composting needs... and eventually supplement the fish diet.I'm estimating no more than 1 worm per fish per day (depending on fish maturity of course). I don't have an accurate rate for worm propagation in my farm, but guess it is currently well below 40/day (I started with ~600). We most certainly generate enough food byproduct waste to support a larger worm farm. I currently have another non-worm compost tumbler where the bulk of our citrus, yard waste, and food scraps go. I've had this going since last winter and have harvested incrementally from it in the course of planting my garden and fruit trees.
Bees
I completed my top bar bee hive at the end of April, hoping to capitalize on swarm season (May-June in Colorado). I was figuring that the previous owners' extensive flower garden would be a sufficient lure to my yard. Unfortunately this year's harsh freeze thaw cycle in April has made it a bad year for both blossoms and bees. I did check around for starter hive kits, but the tough year has raised prices above $400- way too steep for me. I can wait until next spring.A typical bee hive population fluctuates, peaking around 20,000 in the summer and dropping down to 2000 or less in the winter. Many individual workers are lost to predation (a mechanism likely to be lost in a simplified CELSS), but many just die in the hive toward the end of summer and through the fall. I've designed my hive with a hinged bottom for collecting dead bees, which I will seasonally provide to feed my fish. Once I have both, that is.