I been changing the filter and the water every other week because my nitrates seem to always slide towards 40ppm according to the easy strips. I usually change 15 gallons but today i did a 18 gallon water change.
I know i need the skimmer asap to keep the nitrates down.[/
In order for Green algae to grow it has to have a few things present: light, nitrate, phosphate and carbon dioxide.
Green Hair Algae can be caused by excess Dissolved Organic Carbons or DOC’s in the water, poor filtration, or using tap water or well water to top off with. If it were me, I would make sure to use RO/DI water for water changes as well as top off, cut back feeding if you haven't already, be sure to blow off rocks and top of sand before water changes so you can get all the waste you can out, and make sure your bulbs are good as well as maybe cut back on light some until you can get rid of it. You may want to think about buying something to absorb the phosphates and nitrates and put it in your filter. That doesn't mean that you shouldn't eliminate the source of the problem however it may help it keep from getting out of control for now.