Does your fish pet have an ich? A tail and fin rot? If you do see them scratch themselves most of the time, then chances are, they have bacterial and fungus problems. I do see fishes prone to such disease because of the water that we gave them. Aside from that, their leftover food that was stuck underneath those stones and pebbles might have caused the water to be cloudy and that is why we need to change their water. Sadly, we don’t clean our tank on a daily basis because of the fact that we do go to work and nobody is going to clean that tank for us. We do clean our tank once a week, but we make sure to put anti chlorine and anti bacterial fluid into their water before we get the fishes back to the tank. If you have 20 to 30 gallons of water in your tank, then you need only 250 mg of anti biotic to be mixed with their food to treat their rot disease. A good one that I can suggest is Tetracycline. This was the most effective anti-biotic we give our fishes. If you gave them 250mg of this dosage, then you need only 25mg flakes to mixed it with and give it to your pets. Fishes bully each other by nipping others fins and tails. So as the owner, you need to separate aggressive fishes and never ever mixed those flower horns with gold fishes and tamed ones. I am sure you already know the rule of thumb with regards to combinations of fishes that you keep. Ich is another fish disease that you need to be serious taking care of. If you see your fishes having white spots, looks like a salt-like speck on the body or in their fins, problems in breathing and loss their appetite to eat, then that is an Ich. This parasite grows and it feeds on red blood cells and skin cells of fishes. Number one rule, separate a fish that has a disease. You need a tank for them to be treated and never ever mix fishes that are sick with those who are healthy because ich is communicable and it spreads fast. You should give Quinine hydrochloride at 30 mg per one liter of water that you have. If that medicine is not available, you can try potassium permanganate I.P. In using this medicine (Potassium), you put a very small amount, enough to make a lightest color of violet. Then soak your fish for 10-20 minutes and they will be just fine. If you still see the symptoms, then repeat the process the other day, not every day or you will kill your fish. It is still best to have your water treated with an easy starter kit that eliminates ammonia, chloramines, chlorine and heavy metals in your water. You can balance the PH by using that same liquid fluid. Remember to have your filter cleaned too before placing it back to the tank. If you have plants, be sure you get it cleaned from moss or such. Hope this helps you to make your fishes healthy and happy swimming.