is this safe?

i work in an office with 3 other guys, we all have fish tanks, me and my boss have saltwater and my 2 co-workers have freshwater.

one of the guys who has a freshwater tank went out to buy Lava rocks from a petstore, relized that they wanted like 7 bucks for 5 lb bag, so we went to home depot, and bought a 40 pound bag of lava rocks (i think it was for grilling or something), and put that in his tank.

and that just seems sketchy to me, but hes one of those guys who you cant tell him anything, ya know what i mean?

 

Yeah I've seen those grilling lava rocks, there bathed in chemicals. Unless he wants to loose his tank he needs to get those out and do a huge WC.

 

I wouldn't put any lava rock in a reef tank. Lava rock is known to have high levels of metals to begin with. I have no idea if it would be okay in freshwater. Lava should be okay, but I wouldn't really trust the purity of grilling lava rock.

 

Lava rock would be fine for a freshwater tank, but I too do not trust the grilling rocks.

 

My momma used to say "Don't put that in your mouth son. You don't know where it's been." I'm still here today so I guess it was good advice.

 

You tried to eat lava rocks?!?! lol, just kidding.

 

Yea, I don't chew too good today.

 

The best part of this is that you can use them for grilling for our own consumption, but they are completely unsafe for fish.....awesome

 

Good point the grilling ones would be. Safer you would think. But if they soak them in chemicals I guess not

 

There are two types of "lava" rock. The first is volcanic in origin and is very bad for reefs. The second, is light in weight and found at LFS. It is a by-product of smelting. Due to the high temps the "lava" rock impurities that can leach into the water are baked out of this material. This is not to say that all man-made lava rock is the same, however, some can be used as base rock with no ill effects.

Having said all that... I agree that if you don't know 100%, don't do it.