So, I was having an issue with undetectable nutrients in tank. Dosed for nitrate and that got up but the phosphate was still undetectable using saliferts kits. I unplugged skimmer, didn't change sock filter for 10-14 days. I also just bought Hannah checkers and checked for phosphate and still got a 0.0 reading(earlier today) About to check alk and nitrate. Is this growing a major concern?