I had SOO much trouble myself with algae. It seemed that I always had some hair growing in my tank. But for a long time it was acceptable, and manageable. Then one day it went crazy. It started over growing corals, and I couldn't find my snails because even they were covered in hair! I tested my water parameters and nothing had really changed. My nitrates always registered a little, but the numbers never changed in any drastic way to explain the algae increase.
To get to the point already, I bought a better skimmer.
I hated the one I had in the beginning anyway, it was noisy and I had to constantly mess with it in order to get it to skim correctly. I bought a DAS EX-1 skimmer. It skimmed in a day what the other took a week to collect, and within a week, All the dark green hair started to turn a light green, within 2 weeks the algae was starting to come off the rocks, and now about 2 months later, its pretty much all gone. very little signs of any left.
If you're testing your water, keep in mind that the results might be a bit deceiving. You may have a lot of phosphates/Nitrates being produced which the algae is consuming and thriving on, and leaving none in the water when you test for it.
Good luck. also one thing that I had happen, after stripping all the Dissolved organics out of my tank in a huge hurry with my new skimmer, it had a slightly adverse affect on a few corals, and gorgonians which required me using more supplements.
