i don't have a phosphate test kit yet (i know I added to the must have sooner then list) but based on my alage bloom and a lack of nitrates in the water I am guessing I do have a phosphate problem.
I also understand that it is just good to have but I want to go with Chaetomorpha Algae cause it is less risky I heard with sexing calerpa can dumb all its excessive nutrients and lead to spikes.