Agree with others, with no corals, you don't need to be testing/dosing elements. For the algae issue, what lighting do you have and how long do you run it each day? With a fish-only tank, you can leave the DT lights off for a few days and just run the fuge light. That will help kill off the nuisance algae and allow your macro to take over nutrient control. (FTR, some don't run supplemental lighting at all on their FO systems). I will suggest vacuuming out the algae as it dies off; otherwise it will create even more nutrients.