Is Lava Rock Safe for Aquariums?

Is lava rock safe in aquariums? I added a small chunk to my tank with a java fern attached to it, however the rock has turned the color of rust... Should I remove it?

 

Hello Cerfew,

Here is your new thread.

Yes, Lava Rock is Aquarium Safe. You may want to keep an eye on your pH levels for increases. It sound like your tank may be dealing with Diatoms which is completely normal especially in new tanks up to one year. It should eventually go away on its own.

You can remove it with your fingers from plants, use an algae scrubber on your glass, maybe a brush on the lava rock. Use siphoned tank water to rinse the rock it. It's porous and contains beneficial bacteria for the cycle.
Ken

 

I've read it is good for a fish tank, helps clean water. I have one in my goldfish tank and no problems. As with any decoration, wash it first.

 

Chemically, its fine and even beneficial, physically, it may scratch the delicate skin or snag fins on some fish. Otherwise, I wouldn't worry about it.