safe rocks?

[Coyne]

I picked up some rocks from a local nursery today. I'll be using them to make a cave for my future crayfish. It was called Wintergreen Marble. Is this going to be ok to use, and if so is there any sort of prep I need to do before I put it in the tank? I'll be gluing them together with aquarium silicone sealant.
Its might be worth noting that I dont even have water in the tank yet and that when I do I'll be doing a fish-less cycle. So it will be at least another 4-6 weeks before there is anything living to worry about in the tank.

 

[Ekiel]

As I understand, the only "negative" to marble is that as a metamorphic limestone, it will raise and buffer the pH. However, crayfish tend to do best in the higher pH ranges, and adding it early in the setup process will allow you to avoid any sudden pH swings. Although, because the pH will likely depend on the buffering capacity of the marble, if you ever decide to take it out you will have to slowly acclimate your tank to the pH of the water you add.

I've never used it myself, so I don't know if the cleaning would be different from any other rock.

 

[Coyne]

I already have a fairly high PH of 8.2 right out of my tap. Could this raise the PH even higher?

 

[Ekiel]

At 8.2? It's doubtful, I'm pretty sure that that's about as high as it would bring the water to begin with.

 

[Coyne]

Well, they passed the Vinegar test with flying colors... so thats good.

I'll put them in a bucket and see if there is a significant change in PH after a couple weeks.

 

[Tieberion]

Yeah at 8.2 it's not going to run much higher, so you should be fine, hope the little guy gets a cool new home!