Cooking LR: Nitrates not going down

[vessxpress1]

My liverock has been cooking in a dark tub for 48 days. I've done 3, 100% water changes and the nitrates are back up at 15 ppm and not going down. It's about 60 lbs of rock. How much longer could this take?

 

[lakee911]

You probably need to do less of a water change more often. Maybe 25-50% every week, in my opinion. The sudden change from a 100% water change would probably cause some die off and cause the elevated nitrates. Do you blow off the rocks and turn them regularly and what not?