Also you're using a python to do water changes, which is totally different than how one does it manually, prime is NOT what's causing your issues unless you're not using it correctly, my opinion is this either you're over cleaning the tank, over doing water changes, not letting the water gas off when you put it back in the tank or not treating the water correctly when you do your water changes... or all of the above. I've been using prime for 3 years and have not one time had an issue. Do you add the prime when you're refilling? Are you dosing your whole tank as you're supposed to with a python water siphon? Are you keeping the vac above the water while refilling so the water can gas off?