I breed a lot of fish. I used to sell them in aquarium clubs to people to people who were glad to get them. Now I live in a small city without a club auction scene, and it's harder to share them out, or sell them to stores.
I breed offbeat stuff - uncommon fish. No store wants platys or the easiest fish - they are so cheap from the wholesalers we can't compete. The same is generally true for plants - you need to produce the unexpected or your products aren't wanted.
I also maintain fish. You don't get to see how they behave in just one generation. You need to take them through two or three generations to really get how they live in tanks.
It's necessary to have several tanks per species, so breeding demands space and resources. It's still way cheaper than golf or fixing up cars, but it is a more demanding side of the hobby, resource and space wise. You need the breeding tank, fry, juvenile and single species community tanks. My oldest species here, a killie that I've bred for 30 plus years, has six tanks, and can go up to eight when people want them.
Money? No. It costs more than it returns. Breeding basically pays for new fish and plants, if you live in a city with a network of aquarists. To have income, you need a talent you can connect to the fish hobby market - designing things, writing, artwork, video-making etc. And even there, the internet has killed most ways of making revenue from aquariums. I made much more than I spent for a number of years, but online, 'everything is free', and that means you breed fish because it's fun.
It's worth it if you enjoy the puzzle of learning how to breed something new, or if you just like to see the full life cycle of a species.
