How old is the tank Miz? Often times a tank needs to mature for a while before it starts to stabilize. When you take liverock out of the ocean and ship it across the planet, there is a pretty good amount of die off. These organisms left in the rock need to break down and this takes time. Also over the counter phosphate test kits are fairly worthless. If the algae is present something is feeding it. I would recommend spending some time reading about phosphate, its effects in aquaria, and methods to get rid of it. This is a fairly important and expansive aspect of the reefing hobby.