Went to a new coral and fish store in my area super nice guys (more on that in a different post later) we were talking and they asked what my Phosphate level was. I don't know was my answer because I haven't been testing for that. What have had is algae that is thinning out but can't quite get rid of. I bought a Hannah tester from them and tested when we got home I got a reading of .05. Is this high, low, or ok and what should I do about it?