Bought These From A Construction Supply Store. Are They Safe For An Aquarium?

[Metallica1175]

They said they're called river slick flat rocks. One of them looks like it has concrete on it. I dropped vinegar on them and they didn't fizz.

 

[Aqua Fan]

Welcome to Fishlore. If you have put vinegar on them and they don’t hiss or fizz, then they should be fine. Just make sure they are solid and don’t fall apart easily and you give them a good clean. Be careful if you choose to boil them as some stones can explode. They should be fine if you just give them a good scrub under warm water.

 

[Metallica1175]

Welcome to Fishlore. If you have put vinegar on them and they don’t hiss or fizz, then they should be fine. Just make sure they are solid and don’t fall apart easily and you give them a good clean. Be careful if you choose to boil them as some stones can explode. They should be fine if you just give them a good scrub under warm water.

Thanks. The rock with the bumps and gray on it isn't concrete?

 

[DuaneV]

They look like our standard "river rock" up here in Maine, and they should totally safe.

 

[grump299]

Welcome to fishlore if it is concrete it will raise your ph fast just watch it... It will drop again in awhile but other then that it is safe for your tank .