My mother in law has a horridly depressing 20 gal hex aquarium. She has a shubunkin gold fish, a common goldfish, 4 cichlids (small, and blue. Idk whabarbs and cherry barbs t kind to he honest) and 3 cherry barbs in there. it makes me so sad overtime I go over there. And she refuses to listen to any info I give her. She's running a 10 gal filter, has never done a water change in the five years she's had this tank, she just dumps new water in when it gets low.
She's got 3 pieces of rotten bamboo floating that she keeps telling me are good for the fish and that the goldfish nibble them.
I offered to take the fish off her hands and rehome them, or donate the goldfish to the museum's pond. I even offered to help her set up and maintain an appropriate tank for the fish minus the goldies. She won't budge.
Those fish are dying slow, tortuous deaths.