Hello I hate to ask for help. After some time I finally realized my fish were breathing heavy from a bacterial bloom. To save the fish I would change the water. Then it would come back. Three fish stores testing my water, with me testing daily I can’t figure it out. Here is a picture before and after of one day not doing any water change. How do I solve this, I have had a UV sterilizer going, stopped feeding for a while, siphon rocks and sand often. Got a way to big protein skimmer that can’t keep up as it over flows with even 1/2 an inch of water. I had to clean slim out of my AIO sump and clean the pumps and tubing. I’m for a loss scared and feeling defeated.