Treating and reusing old rock, and phosphates...

[Joe Batt]

Just restarting an old tank and wanting to make sure the rock is 100% pest and phosphate and problem free.

I bought around 40Kg of rock from a guy that had removed it from his tank around a year ago and it has just been sat around dry since then. However, I don't know or trust the history (I'm just suspicious like that no other reason) and worry it could have pest issues or phosphate issues.

Since it's not been in water for a year would it be safe to assume everything is 100% dead, aptasia etc don't survive that long or re-emerge when re-hydrated?

I am thinking of giving it a beach bath for a day or two then rinse, drying in the sun, then RODI with a declorinator. Would you guys think that's sufficient for any latent pests?

After its 100% pest free, what is the best way to check it doesn't have a hidden phosphate problem before I go through the process of re-seeding and curing it to bring it back to life?

 

[foxt]

I did this with dead rock about a year ago. I don’t think you need to worry about any pests, it is the organic left behind when they died that you need to get rid of. Give the rocks a short bath in diluted muriatic acid to etch off organics. Rinse them, then start soaking them in a brute of saltwater, heated, with a small power head. Check the water for phosphates. If you start seeing phosphate, start dosing seaklear to bind the phosphates. Continue until phosphates are gone.

The whole process took me about three weeks, but my rock was fairly clean to start with. Watch the acid bath though, it can eat away the rock fairly quickly. There are numerous threads on here about this approach, even some videos on YouTube ....

 

[Randyp79]

Acid bath and then soak in RO/DI. I always see people saying soak in saltwater, but it's faster if you soak in RO/DI. Rate of diffusion is based on concentration gradient, and since RO/DI has 0 TDS, it's like a chemical sponge. Also, look into lanthanum chloride to bind phosphates being leached from the rock, it'll speed up the process too.

 

[Joe Batt]

I am a bit wary of using Muriatic acid (I know nothing about acid except it can be very nasty stuff), so I am more inclined to a bleach bath for a week or so. I'm in no great hurry.

 

[Randyp79]

I am a bit wary of using Muriatic acid (I know nothing about acid except it can be very nasty stuff), so I am more inclined to a bleach bath for a week or so. I'm in no great hurry.

Use vinegar then...

 

[Joe Batt]

Is vinegar better than the bleach? At what dilution and duration?

 

[Som1else]

I don't know if its an accepted practice anymore but it used to be popular to "cook" your live rock and let the bacteria do all the work. Whatever you do, do not put it in the oven and bake it. There was a thread awhile back where someone almost killed themselves with the fumes from baking their rock.