Hello! Just over a month ago, I started up my first 20g freshwater fish tank. So far I have five cherry barbs, one dwarf gourami, a spotted Raphael catfish, and a beta fish. All has been going fairly well, but about two weeks ago I noticed a few of my barbs having long white stringy waste (which I read was a parasite). I then added a paraguard to the water which seemed to clear the problem. Although last night I caught a glimpse of my catfish and now he is very pale and seems almost skinnier than normal. He's been taking a while to come out after I turn out the lights when he used to come out right away. I'm nervous the paraguard might have hurt him, or could it be something else?? Just today I also noticed the stringy waste again (this time on my gourami) but I'm too scared to add the paraguard. I'm terrified I might be losing my beautiful catfish. Someone help!