too much phosphates
So what are sources of phosphate? I got an API phosphate test kit a few weeks ago. At first my phosphates were low 0.5 ppm so I was adding potassium phosphate as a dry fertilizer. Recently I have been having high phosphates 5-10 ppm and I have obviously not been adding any more dry phosphate. Where could these phosphates be coming from. I have 7 guppies in the tank and a lot of snails. I am dosing KNO3, Sechem Comprehensive, and a small amount of excel for spot treating black brush algae. I do water changes once a week which brings phosphates down some but then they come back up as the week progresses. I am feeding Hikari tropical fancy guppy food which says min 1% phosphorus. Am I over feeding? I should also add that this is a 20 gallon tall dirted low tech tank with 3 T5 NO lights. Should I worry about having phoshpates that high? If I recall I want them around 1ppm.