I need help please! My water readings are 0 ammo; 0 trites; 20 trates; 7.2 PH. I do 25-20% weekly water changes, gravel vac and change filter monthly. My gs were bought a month ago. I have 2 platies; 2 ottocinclus and 5 neon tetras in my tank. There's no sign of a worm in any of the gs, only this white discoloration throughout, they are eating and swimming around, except for the whitest one who is now looking almost yellow, and hiding under a plant, not eating.