Gnomecatcher- that theory sounds like it could be true in my case. All these plants are slowgrowers except the hydrocotyle. I may turn the co2 down a bit, although algae is not bad right now. Hate to change anything right now for the fear of outbreak.
If you do change CO2, change it very slowly so the plants have time to adjust. I think the problem is that algae is so good at adjusting to changes in CO2, that if there was suddenly less CO2, the plants would have a harder time with the uptake of the "hard to get" CO2, but algae would make the change very swiftly and smother your plants.
Update: pulled the hydrocotyle and replaced it with a different hydrocotyle haha. Other than that the crypt nurrii has completely carpeted the back portion of the tank! Now its slowly filling in the rest of the tank. I think it looks pretty awesome. I know the bolbitis is way to big for this tank but the clown killies hide in it since it reaches the water surface. I'll replace it with something with a better scale someday.