Actually, the bacteria in the sand feeds on the ammonia/nitrite. Like most bacteria, it's pretty hardy also. Adding fish food or any other organic substance will only increase the ammonia/nitrite and add to the cycle time. I wouldn't do anything for a while except monitor the ammonia and nitrite levels. Don't bother testing for nitrates at this point...just wasting test reagent. When the ammonia starts to drop, you'll see the nitrite begin to rise. It'll take a little longer for the nitrite to cycle since the bacteria that processes nitrite grows at about 1/2 the rate of the ammonia eating bacteria. When the nitrite has dropped to 0, do a water change and check for pH, ammonia, nitrite, and nitrate. Add buffer to correct the pH if needed. When you said "base rock", I'm guessing you're talking about rock that had some life on it, but not really nice live rock? If it was all dry rock, you'll need to get a few pieces of LR
to add to the tank. This will get the coraline algae started. You could also order some of the Garf Grunge from www.garf.org
. They claim it is loaded with coraline and sand critters. In order for your sandbed to function properly, you have to have the critters (worms, amphipods, copepods, ect...). Another option is to get some sand from a well established reef tank and add it to yours. I'd wait till the tank was cycled before doing this. If you get LR
from the LFS
or from a friends tank, keep it underwater while you transport it home. This will minimize any die off and keep you from having the tank go through another mini cycle.
You mentioned a wet/dry filter? Is it full of the dreaded bio balls? Your rock and sand will take care of your biofiltration so you won't need the media in the wet/dry. The bio balls will only cause you to have high nitrates which you don't want. I'd like to hear more about your tank. What kind of lighting do you have? What kind of fish/inverts do you want to keep?