I saw a lot of green dot algae on the glass and on the leaves of the plants. I currently have co2, 10k 220 watts (2 white and 2 actinics, will switch to all white bulbs soon), 11 hours of photoperiod. What can I do to get rid of these nasties? My shrimps and 2 Pleco don't seem to help.
I had the greenspot problem for a while. Manually scrub it off (might be harder than you initially think, but it will come off with elbow grease). Drop your photoperiod to 7-8 hours a day. Those things thrive on excess light. Cut it back and you should see a reduction in the prevalence of the green spots
I would reduce the photo period to more like 6-8 hours and evaluate the nutrient situation in the tank. Adding more phosphate to my fertilizing regime has nearly eliminated all GSA in my tank. The little that develops is much softer. I used to pop it off with a razor and now an easy going over takes it off. I use a Mr. Clean eraser too, the original one is fine for aquarium use.