Constant Algae In New DWC ... Advice?

Hey guys. I have an 18 gallon DWC with 3 air stones, T5 CFL ballast over it, top completely covered in foil. These seedlings have been in for about a week. My ph stays pretty constant until the algae comes. I know when I can't keep the ph down, algae is in full effect and I do a res change and wash, rinse and put back together everything. I thought maybe that some light was still gettin in through the hydroton so I cut squares of foil and put a whole in the middle to go around the seedlings so the foil covered almost all of the netty pot completely. Here is a pic and any advice is greatly appreciated.

Oh, & here are pics of the 3 plants in. One looks like it's leaves have turned brown died and broken off. Poor thing looks terrible. The other two may survive if I can get this algae under control. If I can't I might just chunk all the shit!

^ bump

By the pics, can I conceal light anymore other than spray painting the tub?

Have you tried h2o2?

I haven't but now that you say that, I remember reading that somewhere. I guess i should just google how much hydrogen peroxide to add per gallon of water for DWC, ya think?