I relate to this topic a lot.
My step father has shown interest in the hobby especially as of late, so together we resealed a 40 gal, built a stand and stocked it. The guy's high stress so I figured a fish tank would mellow him out, give him a creative outlet, maybe a small sense of accomplishment.
The problems come when feeding, water changes and lighting schedules are discussed. I try to keep things simple like feeding once a day, limited light, and me personally handling water changes, but the tank can't seem to stay the way it needs.
He likes to feed multiple times a day, wakes at 4 am and lights the tank till 10pm most days. Were now running into a bit of an staghorn algae problem. I've tried to explain the science behind low feeding/light but I get the impression he thinks I'm trying to 'outsmart' him. He then does the exact opposite, as if to spite me. We've argued about tank Temps, the 40 is stocked with an oranda goldfish, 6 danios, 1 hillstream loach and some cherries. Colder temp fishes so I try to keep the temp around 70 also to slow down metabolisms a bit, but often find my heater adjusted to 76 or 78. Any conversation usually turns into a bit of an argument at the expense of the fishes, well kinda, they usually get more food afterward.
As my love and knowledge of the hobby grows, i feel compelled to try and fact check or lend my thinking. Its definitely a balance. Lately I've been putting CO Op videos in the background that roughly relate to the tank, in an attempt to give him info from someone else who he may listen to. I view it as a learning process, though I'm not sure if I'm truly helping him learn since I'm sort of micro managing the tank. Would it be cruel to let him take his lumps at the expense of the fish?