Cleaning and curing "formerly" live rock

Back when I had my first saltwater tank (late 1980's), everyone would bleach their rock (which was just coral skeletons dyed different colors) once a month or so.

To remove the bleach before putting back in the tank, we'd soak the "rock" in another tub of tap water (I know...I know...) with a product called Fritz guard. It got rid of any bleach that the rinsing with water didn't get.

 

I have some rock in a 5 gallon bucket with saltwater, no power head or current. The rock used to be live but I let it dry out. Now since its been in the water there are red things growing on it, anybody know what they are?

 

Appreciate all the responses. I'll place the rock in my basement in a large bin I have with a powerhead circulating the water.

Should I rinse it BEFORE placing it in the bin? I didn't realize the rock would become clean by curing it. In the rocks I already used, I found old hermit crab shells that were stuck in small holes, and lots of detritus and other gunk.

 

Yeah, rinsing it will pull off a decent amount of the detritus that's built up. It'll make the cycle a bit shorter, hopefully.