Swifterz

these things are there for the taking all around me IF it's safe to use. i have no idea what it is. that isn't dirt on the rock though. it's been thoroughly rinsed and scrubbed. that's just it's coloration.

can anyone identify it? will it be ok in my tank?

aquarist48

Good morning Swifterz...I know we have a geologist or two as members that I'm sure will help you shortly. One thing I know you can try is, drop some vinegar on the rock and see if it fizzes. If it doesn't fizz then chances are it may be ok to use. Let's see what some others have to say. Have fun on the site

prairielilly

Hi

It looks like a piece of limestone to me, possibly dolomite. I'd try the vinegar as Aquarist suggested - if you get fizz, it's limestone; if you don't get any fizzing, try scraping a bit of the rock off with a dull steel knife. If you can do this, put some vinegar on the powder and watch for fizzing. If it does, it's dolomite. If you can't scrape any of the rock into a powder with a knife, it is likely sandstone, but I think that's unlikely here.

Limestone is calcium carbonate and dolomite is magnesium carbonate; your rock may even be a mixture of the two minerals which is not at all uncommon. Both these minerals will dissolve slowly in water and in so doing add minerals to the water and also raise your pH. They will dissolve faster if your native pH is less than 7 (acidic) and more slowly if it's basic (over 7). Depending on how often you do water changes you may counteract this effect completely just by removing water. It may even be something you want, if you're keeping certain cichlids or other fish requiring a high pH. If you have delicate fish or those preferring an acidic/soft water environment, I'd reconsider adding the rock.

hth,
Marsha

Swifterz

thanks for the info. i have decided not to use the rock, but rather just purchase a rock or two from the LFS. i really only need one for what i am trying to do. i have this idea in my head and i think it would be awesome, i just have to find the right rock.

prairielilly

If you were to find one in a natural setting (no risk of pesticides etc) you can boil it to sterilize it. I'm a big advocate of NOT paying for rocks...

Hope you find one you like, regardless!

Swifterz

wait, will this (lava rock) be safe for use?

http://www.lowes.com/lowes/lkn?actio...568&lpage=none

there is a Lowe's like 12 seconds from my house...

prairielilly

It's pretty hard to tell from the pic in the link, but it might be rhyolite, which is often pink or red. If it is, it's exactly the same chemically as granite and therefore safe. 'Lava rock' often refers to vesicular basalt (rock with lots and lots of holes in it) which is also safe chemically, but has lots of sharp edges around the holes. This rock is approximately the same hardness as steel and so you won't be able to file it down. If it doesn't have tons of holes (isn't sharp-edged) then I'd pick it up and see if it's relatively heavy ('rock'-like) - if it's really light and of low density, it isn't really a rock (I wondered about this bc of the listed uses of it). In sum: should be ok, just check the edges and heaviness things.

http://en.wikipedia.org/wiki/Rhyolite

Regal

Lava rock is commonly sold in fish stores as aquarium safe. I'm not sure if that is the same thing or not. Since it's sold for landscaping and not for fish I don't know if it might have chemicals on it. (no reason why it would be sprayed with chemicals though lol)

It looks like the same as the fish store lava rock to me. I've had that in tanks with no problems.

SCUGrad

I found the rocks in my 75 gallon tank on the sidewalk outside my house. Did the vinegar test, brushed off the dirt, rinsed it thoroughly and plopped it in the tank.

gmen4life

i found mine in the river boiled them and let it rip now i need more for the new tank

kimb

My 2 55g are done with river rock found outside my house (thanks Prairie for all rock info, you are still the queen). I would boil anything you decide on first, including those from the LFS. I too won't pay for what I get for free, half the fun is searching for the perfect rock. Good luck!

navyscuba

I would go to a stone/landscaping place to save some the fish stores charge extra for these kind of rocks. I would use a river rock, limestone, slate tile is good too. Good Luck.