Rub a leave that has it between your fingers. If it's slimy it's likely not GDA and could be a type of BGA (cyanobacteria).I'm not sure which green algae is on (some) of my plants. All I know is that it is green. I also cut back on duration and cut out my midday burst. It has helped a bit.
The graph is for plant photosynthesis absorbtion rates for the different chlorophyll and such that plants use in the photosynthesis process. I think I got this graph off of a university website site that was doing experiments on photosynthesis. Over the years I have collected many different graphs while researching plants and lighting. I'll see if I can find the website. It was a good article as I remember.Newt, just to clarify is that graph for the cyano or for the dust algae? I've never read about that before, pretty interesting stuff, do you have a link to a larger article? I'd like to read more about it.
Not sure what you mean by flat to the leaf. I just call the stuff plain green algae that grows in healthy water.if it is rough it is more likely another algae and not GSA. Is it flat to the leaf? AC