I have had green hair algae growing in my tank for a while now and it’s really starting to be a problem. At first when I didn’t have any corals I would be able to use a tooth brush and just clean it off pretty easily. But now that I have a tank full of corals I have the same problem in a different way. The hair algae is growing in between corals such as my zoanthids and around sps that I cannot move to scrape the algae off. I only dose magnesium as of right now and I only test for ammonia, nitrite, nitrate, pH, and magnesium. I would be able to get some other test kits but I was trying to avoid it until the corals start needing other nutrients I would need to dose. I was mainly avoiding it because for a good test kit in my area they are around 30$ for each different level. By levels I mean calcium, magnesium, phosphate, etc. I’m just looking for some advice. Thanks