Hi everyone. I went through the faq prior to this and apologize if I am repeating a post. I've had my male Betta for 10 months now and he acts happy and eats like a pig. However, his fin rot won't go away and I want to ask if I am doing something wrong as far as water goes. He is in a 5 gallon hex tank with a filter and heater. All decor has been tested to make sure that he can't hurt himself when he swims by them. What I do when purifying tap water is add Seachem Prime and some stress coat for the rot. I also add aquarium salt to the tank. When I first got the prime, it got the job done by purifying the water by the next day. (I use the solutions kit to test.) However, now the water is still contaminated even after purifying with prime. Does it expire w/o me knowing? The company said it doesn't. How do you purify your water? Do you add salt each week with each water change? I add once a week and have been buying petco freshwater because my tap water isn't purifying.
Also, he got like a bruise on his forehead. He is a dark blue Betta and the bruise looks much darker, almost gray/black. Not raised, looks more like a scar. Am afraid it will get infected more along with the fin rot. Please help!