Planted Tank Guru
Join Date: Jun 2004
Location: Baton Rouge, LA
10,000k may not be exactly optimal. But I'd say if it caused this big of a problem, then it was just what pushed the tank over the edge; and you have other, more severe problems.
Did you replace the ferts you removed with all those extra water changes?
Why are you running CO2 so high? What's your pH?