[SpeedEuphoria]

Test your nitrate levels, its prob at 0, which is bad. As another stated API leaf zone is only Iron and phosphate.

So you deff need some nitrate and potassium will help as well as a trace.

Excel will likely kill off some algae, but not fix your prob as its a carbon(CO2) substitute and you already have CO2.

I'm currently running 2x 20w CFL's(10hrs) on my 10G and no CO2(excel) and have to dose minimal ferts. With CO2 I would have to dose more ferts as well as with more light.

In the mean time reduce your lights to 6hrs and/or reduce it to 2 bulbs. Then get some ferts that your lacking and let it clear up. Then slowly add more light back in over a month or so.