Just thinking what to feed the fish if SHTF . Was think massive worm bed,recycling vegetable matter from the aquaponics system might be able to sustain it self.
As for fish you would have to have a way of reproduction and if there was no power so no heat would limit your fish to Bluegill ,Catfish and Koi. Bluegill would be easy as for they are every where and easy to catch and restock. Catfish would need a big pond to reproduce and Koi yech!!!!! As for power you would have to go with solar.
SHTF : Sh!t HITS THE FAN
Worms on their own are not a complete diet for fish. Too much fat. Need to diversify some.
Now it will depend on exactly which type of fecal matter hits the rotational air moving device as to what will work. I mean if we are facing nuclear winter, there could be too much dust in the air for solar to be functional for a couple years. In which case some for of generator and some sort of fuel to burn in it or mechanical/manual will be the only way to go for a while. Provided you are not in immediate danger of dieing of radiation.
Bluegill I've heard will re-produce in a swimming pool size system without extra attention from the humans, at least some one in TX told me their bluegill in the pool had babies. I haven't had mine long enough to know what will happen in a 300 gallon tank but I haven't noticed any babies after only one year.
I've heard Catfish could reproduce in a cubic meter tank provided that you were certain that the mature pair of fish were one male and one female with an appropriate "cave" for the eggs to be laid and the male to stay and fan his tail over them. I've not tried this, nor do I know anyone else who has done it and I'm not certain of telling gender in channel catfish without cutting them open to find the eggs. But if you have a fair size farm, I'm sure you could breed some channel catfish in the pond.
Now keep in mind should SHTF happen, there are many more options for food that Main stream US society turn it's noses up at. I'm sure we will rediscover the fine art of eating squirrel, opossum, raccoon, rats, and many of the other "pests" we currently do battle with. There will likely no longer be an unwanted dog and cat population in most places anymore either. Breeds of chickens that are good at free range foraging and brooding/hatching their own clutches will suddenly become very valuable. Muscovy Ducks are already a good choice of bird that can to a large extent fend for itself and breed prolifically. Rabbits and guinea pigs are other animals that can be fed largely on grass and weeds.
I'm curious about being able to drink the water in a system. I'm thinking 2-4 week interruptions of modern life wherein my animals all become meals and water tanks get emptied out for drinking. The tank water looks a little nasty but besides the off flavor do we worry about bacteria or whatnot? Whats the best treatment?
I know people who have sampled their system water and they are alive. In a major emergency where you "had" to purify and drink your system water for survival, I would probably use hydrogen peroxide to kill off an abundance of the bacteria but I can't stand drinking chlorine flavored water from treating with bleach.
I have a hand pump membrane purifier that I have used on hikes in South American jungles and probably would use that.
aquaponics in that type of situation makes a lot less sense than raising rabbits, ducks, quail, chicken etc..
if you want to raise fish as a "prepper", your best bet is to build a pond or two that can be managed for your goals