Hello....I have a simple tank: 40 gal f/o, c/c sub, bakpak2, All readings are excellent with exception to nitrate which is .40. I have 1 small yellow tang, 1 clarki, 1 marron clown, 2 green chromis, 1 cleaner shrimp. Questions are : 1. I am running into an algae problem to which I have been...