Hi, I have a black moor fish showing signs of sickness. The tank is a 20 gallon. His tank is normally really clean and he has rarely been sick. His eyes look like they are protruded and he has white stuff growing on the top of him. He is normally really active doing laps around his tank, but lately he’s been lathargic. I did a full water change with distilled water, because I thought it was ick. But, it hasn’t cleared up and the medicine for ick is turning the water blue. I tested the ammonia and the ph- both were really low so I put a water fizz tab for ammonia. I do not have a very good test kit it just gives me colors and tells me if it’s stressful or acidic. I also put water clearer in the tank after I changed it. Is the ph caused by the low ammonia? And how can I prevent this in the future?