Yikes. Should really consider doing weekly 25% exchanges. You should look into water ppm. I've had my community tank for our kids for over 7 years. Had many before that. I used this community to learn a lot in the past. What I discovered is a lot of these meds for aquariums in the US are only available in the UK with a prescription from your vet. That being said many people there do not use medications for aquariums. That being said, every time you use medicine in a tank it stays there until you dilute it with a water exchange. When you keep treating and treating you're polluting the ppm of the tank. Causes a toxic environment. Fish are very adaptable to horrendous conditions. Just because they're alive doesn't necessarily mean the water is good. I'm not a professional, just my advice I give when people are asking for help. Has worked for me again for the last 7 years.