Hanzo

I'm having a slight problem with green spot algea growing on old leaves, mainly my L. Repens, but also a couple of other plantes. I think I got this by dosing wrong, my NO3 was around 15ppm, but traceelements and iron was close to zero. But for some darn reason, the plants that was "infectet" during this still seems to grow alge on the leaves. The top of the plant, and the next three setts of leaves are fine, but then the algea start popping up on everything below this. Would it help to cut out the part with algea on it, and just replant the clean part, or is there anything else I can do? I read somewhere that dosing Phosphat would help against green spot alge, but I'm kinda worried about doing this

aquoi

My won battle over green spot algae on old leaves tells me that too much light and not enough CO2 is most likely the cause, or low nitrates.

bms

aqoui,
my L.repens have what I think is green (brown? if it exists) spot algae.
My CO2 level is fine, Ph 6.4, Kh 4... I am not sure about Nitrates though, the color I get from the test does not exactly match any of the colors on the chart... I think it is between 5 and 10, but am not sure...

Should I dose more KNO3? At what point do Nitrates become a problem, in case I am overdosing?

I am only dosing about 4 ml Flourish a week, could this be the cause?