Cleaning Old Rock

Shep · Jul 5, 2015

So i have a bunch of old dry rock that has been sitting on my back porch for about a year(uncovered), is there anyway to salvage it or is it a lost cause? I just really like some of the shapes of the rock and would like to save it if possible.

FlyinBryan · Jul 5, 2015

Absolutely! Id cycle it for like 2 months but should be fine!

Shep · Jul 5, 2015

Just put it in my tank when I set it up? Should I soak it in RODI water first?

Randy Holmes-Farley · Jul 5, 2015

It need not soak, but rinse it well.

The rock itself buffers against the acid pH, so it isn't a big concern. If the pH is below about 7, the rock itself keeps dissolving until the pH rises.

Randy Holmes-Farley · Jul 5, 2015

What was it getting exposed to?

I might acid wash it first.

Shep · Jul 5, 2015

So even though it has been sitting out in the rain and snow, I just need to rise it off and its good to go?

TMN · Jul 5, 2015

I usually have a small selection of old live rock which has been sitting outside or in a bucket for months to a year.
When I need rocks for scaping and don't want to fork out additional cash this is what I do:
A quick spot check, clear/pull off bubble algae or unwanted hair algae that dried up or halimeda or any other nuissance (not sure if their remnants will become zombies, I do it just to be safe). Rinse with hose water if needs pressure to clear off dirt/debris, then I rinse/cleanse the rocks under my RODI water. You can let it dry again in controlled environment or I typically add them after the RODI rinse if I'm landscaping.

I am a believer of the RODI rinse, some may say different.

Randy Holmes-Farley · Jul 5, 2015

Shep said:
So even though it has been sitting out in the rain and snow, I just need to rise it off and its good to go?

Not in my opinion. That's why I suggested acid wash: to remove organics and phospahte on it. If it looked really cruddy I'd bleach it first.

Shep · Jul 5, 2015

Randy Holmes-Farley said:
Not in my opinion. That's why I suggested acid wash: to remove organics and phospahte on it. If it looked really cruddy I'd bleach it first.

So bleach, then acid then RODI?

Randy Holmes-Farley · Jul 5, 2015

Shep said:
So bleach, then acid then RODI?

That is a good plan for the worst rock (like coated with dead organisms such as algae), but I'd rinse the bleach off before acid for your own protection so you don't make chlorine gas.

Shep · Jul 5, 2015

Randy Holmes-Farley said:
That is a good plan for the worst rock (like coated with dead organisms such as algae), but I'd rinse the bleach off before acid for your own protection so you don't make chlorine gas.

thanks! about how long should I do each step for and what concentration of bleach and acid?

Randy Holmes-Farley · Jul 5, 2015

Shep said:
thanks! about how long should I do each step for and what concentration of bleach and acid?

I'd use 1 part acid diluted into 10 parts Ro/DI. How long to leave it depends on how much water to rock volume. It will stop on its own after a while, but an hour may be adequate.

With bleach, fumes are the concern with full concentrated, but it works better (faster). Maybe soak overnight in bleach and see how it looks.

mfinn · Jul 6, 2015

After the bleach soak, I usually do a soak in a strong dechlorinator solution, before the acid bath.

Shep · Jul 6, 2015

mfinn said:
After the bleach soak, I usually do a soak in a strong dechlorinator solution, before the acid bath.

What product do you use or just the typical tap water treatment stuff? Also where do you all get your acid from?

mfinn · Jul 6, 2015

Shep said:
What product do you use or just the typical tap water treatment stuff? Also where do you all get your acid from?

Acid from Lowes in the paint department, and the cheapest dechlorinator I can find.
Usually the API Tap Water Conditioner.
People like to recommend Prime, but that's usually a little more expensive.
When I use the dechlorinator, I use way more than I probably need.
Better to use too much than too little.

Shep · Jul 6, 2015

Awesome! So if the rock is not covered in dead stuff would I still need to do bleach and acid or would just one work well?

mfinn · Jul 6, 2015

Shep said:
Awesome! So if the rock is not covered in dead stuff would I still need to do bleach and acid or would just one work well?

I would.
You never know what is down deep in the cracks and crevices.

Shep · Jul 6, 2015

Awesome, thank you. So the plan is O/N bleach soak, rinse and dechlorinator, acid bath for ~1 hour, RODI soak O/N and then a second RODI soak for a few hours. How does that sound?

Randy Holmes-Farley · Jul 6, 2015

Shep said:
Awesome! So if the rock is not covered in dead stuff would I still need to do bleach and acid or would just one work well?

If you do not see visible organic matter, I'd just use acid.

mfinn · Jul 6, 2015

Shep said:
Awesome, thank you. So the plan is O/N bleach soak, rinse and dechlorinator, acid bath for ~1 hour, RODI soak O/N and then a second RODI soak for a few hours. How does that sound?

Sounds like a plan.
But as Randy mentioned you could skip the bleach bath.
If it was already really clean and sun baked, I might too