Planted Tank Guru
Join Date: Nov 2009
Location: Missouri united states
Look's more to me like rasping damage from possible Pleco ?
Maybe pottasium (K2SO4) could be increased, and see what result's are after a week or two.
Am only guessing on the pottasium, due to it being utilized by plant's fairly quickly according to plant guru's.
I might be tempted to increase all macro-micro nutreint's a little and note any changes after a week or two.