Can I put lava rock and rainbow rock in a saltwater aquarium? (make, place)

[pvjd]

I am considering setting up a saltwater tank. I know the tank needs live rock, I am just wondering whether I can use some lava rock or rainbow rock to add to it for hiding places, etc., or if it will make it uninhabitable for saltwater fish.

[HookTheBrotherUp]

Originally Posted by pvjd

I am considering setting up a saltwater tank. I know the tank needs live rock, I am just wondering whether I can use some lava rock or rainbow rock to add to it for hiding places, etc., or if it will make it uninhabitable for saltwater fish.

What do you intend to keep in the tank? Neither will pose problems, however, neither will look natural in a saltwater aquarium.

[pvjd]

Fish only, no live corals. I think the rainbow rock would look a bit strange, but was hoping that the lava rock would at least blend once it gets a little algae on it. I don't know, the reason I am asking is because I was told by a guy that the lava rock has high metal content, and over time might seap into the water causing an issue with water quality.

[HookTheBrotherUp]

I would agree about the lava rock possibly being "iffy". I guess it would depend on where you got it from. About the only thing I would trust in my tank is black lava rock from Hawaii... that's been in the ocean already.