Hi all,
Wow, alot of really great input on this thread. Much more than I expected to get. As promised I have some pics of my process. Thought I'd post them along with a "re-update" of my update in Nov.
<b>Background</b>
<li> B/c my tank was up and running with a few fish and coral, I did this in stages so as to always keep some live rock in the tank. More importantly, I did it for seeding purposes - want to easily seed the cleaned rock.
<li> Specifically, I did it in two batches (a total of about 250 pounds).
Here's what a batch the rock looked like right before I started (keep in mind this is AFTER I tried to "cook" it a few times - at one point almost every inch of rock was covered in thick hair algae :hmm6: )
<b>Step 1: Bleaching - Round 1 </b> - As I have learned from this thread, bleach will "Oxidize" organic material on the rock, which basically means it vaporizes anything that is alive or once was (of course the gurus on here let me know if I have that right)
<li> First, I soaked the rock in a tub of water and bleach. About a 3-1 ratio seemed plenty. Luckily my local Costco was selling it for 3 large bottles for like $15! I say a 3-1 ratio b/c after a few days I smelled less and less bleach and no bubbles. For awhile the water was yellow and some tiny bubbles (oxidation?) came up.
<li> I wound up leaving it sit for well over a week simply b/c I didn't have time to work on it. By then all of the bleach smell in my basement was gone and there were no more bubbles. Occasionally I'd swish a few pieces to see if anything came off. Almost always the water turned cloudy.
<li> Eventually I removed all the rock, swishing it as I took it out. The result was a thick layer of sediment in the bottom of the tub. I'm guessing this was just rock/calcerous material and not dead life. The bleach killed anything alive and pretty much dissolved it.
<b> Step 2 - Bleaching - Round 2 </b>
<li> Yep, I rinsed the tub and started all over - did a 2nd round of soaking in the tub, just for kicks. No idea if it did anything or helped. Did another round of swishing as I took it out.
Once again the tub was filled with sediment, but much less. At this point I'm think its really just residual rock/sand and if I kept bleaching I'd keep seeing this sediment. And the rock definitely smelled. My wife has a blood hound nose on the front of her face :eek1: so I asked her to check. She said, "Ewww, smells like the pool at the YMCA!". So I knew I did good.
<b> Step 3 - Playing with Acid </b> - The reason for this, as I've learned on this thread, was to try to remove an outer layer of Phosphate that might be on the rock. Interesting thought so I did it.
<li> After risning I filled the tub with a mixture of water and acid. Used Muriatic Acid from the pool store at a 10-1 ratio. The ratio seemed to work good.
<li> <b>With gloves and goggles on</b>, one by one I dipped each piece of rock in the tub. A TON of fizzing and bubbles occurred. For some reason the bubbles were a rust color. I noticed the rock didn't look any different or cleaner but it sure was fun
Here's a shot of a 5 gallon salt bucket filled with water and acid and after dipping my rock.
<li> The end result was a layer of crud, rust colored gook in the bottom of the bucket. So maybe it helped.
<li> Also, I think this helped to dissolve some or all of the residual from the bleach since it didn't smell nearly as bad. Who knows?
<b>Step 4 - Air Drying </b> - In an effort to release any residual bleach I decided to let the rock sit in the fresh air and son - one approach I've learned here. Another approach I saw someone mention was to soak in water.
<li> After rinsing the rock, now in RODI water, I let the it sit outside for a few days in the open air and sunlight. After 3-5 days I brought the rock inside
<li> To see if the bleach was removed, I soaked it in a tub of RODI. I bought a pool chlorine test kit (redfishsc - wish I knew about the walmart deal!) The test showed no chlorine.
<li> Note: My real plan was to set aside a batch of water directly from my display tank, measure all parameters (PH, etc) and put some of the rock in it, keeping it aerated and at the same temp. If there was no chlorine and the params stayed the same, I'd really know the rock was safe. But, alas, I was too eager to get moving!
So I was left with a nice batch of very clean, white, light rock. It was very chalky to the touch. I spent alot of time aquascaping the new rock using PVC pipe.
<b> Step 5 - Test Run </b>
Once ready I dumped it into the tank with the existing, dirty, live rock and let it sit for about 2 months. The goal was to "seed" the new base rock.
<li> It was bright white under the lights when I first put it in. Looked Awesome!
<li> But, as expected, eventually it started to "color" up - ie: get duller, a little brown - as life started to grow in it.
<b> Step 6 - Rinse and Repeat </b> - Once I felt the new rock was seeded (about 5-6 weeks), I repeated the whole process with the rest of the rock (save for about 10lbs just in case).
And after aquascaping that batch I put it in the tank and I now have a tank ful of shiny new rock

It was really white at first but is now starting to fade. No issues with the fish I have in the tank or with high waste levels. I'm making sure to do frequent basting of the rock to help keep it clean.
Here's a few pics - you can see the rock on the left is the 2nd batch while the set on the right is the first that I put in the tank. Notice the differnce in color. Batches were maybe a month apart.
Overall, while it took a long time - maybe 3-4 months b/c of other projects.
I'm very happy with the approach and would recommend it to anyone.
Good luck and thanks to all who participated in the effort!