Hey guys, I was wondering if anyone else has a friend or friends who keeps a tank and has kept tank for a nice chunk of their life but doesn't believe in water changes... I have a friend who currently has a 20 gallon that's overstocked, improperly stocked (4 dwarf gouramis, a common plecco and other improperly sized schools), and under filtered. They don't do water changes. Luckily the tank has hardy species. I tested their nitrates for them to try and show him how bad it was. My kit goes up to 100ppm, well the red was darker than that red, almost a brown. He claims he called his buddy up at the Chicago aquarium and his buddy told him 10% changes monthly, if that. Furthermore, my friend who lives with them also has two of her own tanks. Luckily she knows how to take care of the fish properly. Well shes on vacation and I'm tank sitting. Problem is that he is convinced that the recent alage bloom in her tank is due to me preforming water changes and he won't let me into the house to change the water. Her poor angelfish might croak soon. He keeps telling me how activated carbon removes ammonia and this and that blah blah blah. How does one deal with someone like this?! He won't believe the internet, he says that people are brain washed into believing the same things as everyone else and that companies like tetra make test kits to convince you the water in your tanks bad so you buy their detoxifyers. At this point ive consider buying a couple of rummy nose tetras, setting two tanks side by side with the same equipment. Cycling the tanks and then I take care of one and he takes care of the other and we will see who's fish looks better. I don't trust him to not tamper though. How do I help this guy???