Treating rock?

[thebanker]

I got some second hand dead base rock that had been left out to dry. I got from a buddy, who is a good guy and a well known name in the hobby. However, he told me that the rock may leach phosphate, since he's had it in his commercial propagation system for at least 7 years; but he's not sure.

I already hosed the rock down with standard Southern CA hose water. I scrubbed it with a toothbrush to remove as much bio-residue as I could, and left it out in the sun for a few days. It rained last night, so I will need to leave it out a little longer I think.

How can I safeguard against the rock leaching undesirables into my system? I've heard that I can:

1. Bleach it, then soak it in RODI water w/ dechlorinator. (not my first choice)
2. Hit it with a pressure washer and hope for the best.
3. "Cook" it in salt water and darkness. (keep in mind, it is already dead)

Any thoughts?

Thanks in advance!

 

[sirreal63]

An acid bath works very well. The bulk of any phosphate will be bound on the outer layers of the rock. The acid will remove those outer layers. You can use vinegar or muriatic, I have done both and both work well. The muriatic is much stronger and works faster than the vinegar. With vinegar I used a 1:1 ratio and with muriatic a 1:4 ratio. Once done, soak in RO/DI for a day and all is good.

Cooking it also works, just a lot slower and probably better for nutrient removal, it just takes much longer.

 

[thebanker]

Vinegar bath is a great idea. I'm going to do exactly that. I figure I could put the rocks in a bucket with a powerhead and vinegar. Should do the trick, right? I dose carbon to my tank as well, so any vinegar left in the rock shouldn't affect my tank much.

 

[sirreal63]

Put a heater in with the vinegar, heat helps the dissolution process. The vinegar won't affect ph as it will neutralize itself, though I did soak in ro/di water for a day after. I did this with the original shipments of Marco Rock (which were quite dirty) and I have never had an issue with phosphates.

 

[thebanker]

Ok thanks. I have a little heater and powerhead that will totally do the trick. I just want the rock to be as clean and dead as possible. Because if it leaches phosphate, then it's using some of my tank's filtration capacity simply by existing. And that isn't cool.

 

[thebanker]

Well, I did it. I soaked the rock in a combination of salt water, vinegar, and RODI. I put in a Hydor Areo pump for flow and microbubbles. Wow did that work well. It took off a layer of brown crap. I can't believe what came out / off of these rocks. I gave them a little scrubdown, and they're really clean now. I've left them to soak overnight in RODI with Kent Superbuffer to hopefully neutralize any vinegar left over from the process. They were brown, now they're nice and white. Success!

 

[sirreal63]

Isn't it amazing what comes off? When you put this rock in your tank, keep them out of high light for a while, the fresh and clean surface has a tendency to grow algae as there is no natural protection from it. The carbon should help, but fresh rock is prime real estate for algae.

 

[thebanker]

I thought about that. New rock does have a tendancy to attract GHA. I'll have to take my chances. These rocks are specifically for the addition to my SPS platform... I was thinking I would put the rocks in, and that same day, rough up some purple coralline to get it into the water, and hopefully I'll see lots of purple spots within a week.

 

[beanoil]

Would this method also work to turn live rock into dead rock? OP--If I'm hijacking, tell me to get lost. It just seems like you folks have some experience with this.

 

[o0jmadr0x0o]

Well, I did it. I soaked the rock in a combination of salt water, vinegar, and RODI.

wait you did it in 1:1 vinager:saltwater?
i thought it was supposed to be 1:1 vinager:water

 

[thebanker]

I used salt water that I diluted with rodi. I added vinegar to that and ran a skimmer pump under all the rock. After about 3 hours of that, much of the brown crap on the rock floated to the surface like a big protein skimmer. That's why I used low salinity salt water. I didn't measure the exact ratios, but i didn't feel that was necessary; I just wanted to create a simple acid bath. It worked. Bleached the rock nice and white.

 

[thebanker]

Would this method also work to turn live rock into dead rock? OP--If I'm hijacking, tell me to get lost. It just seems like you folks have some experience with this.

I suppose it would turn live rock to dead rock... Eventually, and with a very smelly journey there. An easier way is to just leave it in the sun. Being in a simulated desert usually kills marine organisms

 

[aleonn]

I was wondering, how long did you put the rock in the vinegar bath?