I had approximately 75 lbs of rock from my old DT, as well as about 100 lbs of dry rock that I got from another member. I do not know where he got the rock, so I figured I would just clean it all.
The following is the procedure I followed:
1. Borrowed a 150g Rubbermaid container from another member.
2. It is best to work outside since you are going to be working with chemicals, so I placed the container out front on my driveway. I placed all of my rock inside the container, spread out as much as possible so that I would not have to fill it too much.
3. Filled with RODI water until the rock was completely submerged (Approx. 50g), did not want to introduce unwanted materials from tap water.
4. Dumped a gallon of chlorine bleach, placed an old 1500 gph Korlia in there for flow ( I really think that this helps), and let it soak over a 24 hour period (or until all of the rock was bright white). Some of this rock was really dark green/gray with coraline all over, I was surprised how white it became even down inside of the crevices and such.
5. After about 24 hours it did not seem to be getting any cleaner, so I emptied the water/bleach mixture and refilled with RODI water and let sit for another 24 hours, then emptied it again and repeated filling and emptying.
6. Refilled with 150g rubber maid container with RODI, as well as a 29 gallon rubber maid container.
7. Then, with long rubber gloves, rain poncho, goggles, and a respirator, I poured in a gallon of Muriatic Acid (Always Acid to Water, not the other way around) that I purchased from Walmart. Placed the Koralia back in the container to help mix the water/acid and flow through and around the rocks. Let it soak for approx. 15 mins. Then I reached in and gently rocked and sloshed the rocks around individually to help wash stuff off and out of the rocks. As I finished with each rock, I dunked it in the 29 gallon container of RODI water, sloshed it around a bit, and then placed it on my concrete drive in a pile.
8. Once all of the rock was cleaned, I once again placed it in the rubbermaid container and filled with RODI water to soak for another 24 hours.
9. Afterwards, I just left it outside to dry for a couple of weeks.
