One of the problems with new rock is leaching PO4 that is bound in the calcium carbonate and from dead organics. The "dry rock" that I'm cycling in a spare tank was giving a PO4 reading of 0.8, and I was beginning to think it would be months before I could use it in my new tank (when it eventually gets here) So...
I thought I'd try carbon dosing. Reading threads around the web, I haven't found any information on curing rocks this way. Lanthanum Chloride, GFO, water changes, but no sugar.
Since there is no livestock, I wanted to OD the tank on carbon, and skim out the bacteria bloom.
Saturday morning I added a tablespoon of sugar, and by the afternoon I had cloudy water. I set my skimmer up in the top, and let it go to town. The result was tons of light colored skimmate, that looked innocent, but smelled disgusting. When I put the skimmer in I added some pure ammonia to keep the tank from becoming nitrate limited.
So yesterday I came home to crystal clear water, with a reading of 0.06!
Last night, one day later, I added another tablespoon of sugar and enough ammonia to bring the level to 4 ppm. I'll test the water again tonight.