What would cause GDA on a fast growing plant leaf???

[bsmith]

I know too much light but I have a TON of co2 and EI ferts. I believe it is from lack of something but I dont know what.

[Riiz]

I only get Green Dust Algae in my high light tanks, and only on the glass. The only way I know of controlling it, is through light duration. Green Spot Algae can be cause by a lack of phosphate.