My father was a farmer who was an early adopter of the Green Revolution. He made a pile of cash in those years. He invested it back into the farm to make it more efficient. So when wheat prices went down, he was sitting pretty good. He retired at 55.

My fish friend had about 30 aquariums in her house. It takes a lot of skill to breed tropical fish. Very narrow conditions to induce mating and healthy eggs. Different conditions for different fish. Last I heard, she had to take out all the drywall in her house. Too much mold. From the aquariums. She would know about overcrowding and pollution.