Liverock After Cycling

How did you clean the rock?

Well, FW isn't good...You probably lost some of the bacteria. For future reference, use SW--it's less stressful for all the organisms onthe rock. FW should be used only for specific purposes--parasites, unwanted crustaceans like mantis, etc. Personally, I would get some pure ammonia and challenge the system--add anough to bring the reading up to 4 ppm, then test again in 24 hours. This will verify if the beneficial bacteria have been compromised or not. A short term exposure shouldn't be lethal, but I'd want to verify that before putting in fish.

And, while I can understand the motive for cleaning the rocks--being patient and letting a clean up crew took care of it, or researching a better method first, would be advisable. Quick isn't always good in this hobby.

Oriongirl is correct up to a point.
If the liverock is dipped in freshwater then it doesnt take long for the water to penetrate into its centre. the freshwater will have certinaly killed off all bacteria that it comes into contact with through osmosis.
Im afraid to say the liverock is probably going to need a full cycle now as it probably didnt need a cycle at all depending how mature it was. You will have probably killed any small pods worms etc and this will cause an amonia spike.

There is no escaping the algae bloom that appears after a cycle. This is the diatom stage and it usually passes within a couple of weeks

You want your live rock to be alive! Brushing off the algae is not what you want to do... leave the brown algae and get a clean up crew... sooner or later better algae will take its place... such as coarline algae (if you have the lights for it) cleaning your live rock will only slow this process.

The main problem isnt the bacteria but the critters that were alive on your rock ie sponges pods ect that have died.This is going to cause an ammonia spike when you put the rock back in the tank........Dont add anything to your tank until the ammonia spike is gone.