Overall my tank is doing very well. The only unsightly part of it is, for lack of a better description, the black spot algae that grows on the leaves of the slower-growing, broad leaved plants (Echinodorus, Anubias). It appears on the older leaves, so it's a slow growing algae. I tried searching the forums and didn't find anything that sounds like what I have. Anyone have any idea what I'm talking about? There is no other algae in the tank. It definitely isn't BBA...I did my time with that stuff!
I have a 75 gallon with about 4 WPG of light, CO2 in at about 2 BPS, ferts I guess would be considered EI methodology, though I change about 40% every 2 weeks instead of weekly. Substrate is 4" of laterite enriched sand/gravel with a 1" peat base. Temp about 77-ish, pH is around 6.6, KH about 3 or 4, GH in the 5-7 range.