Is this rock safe for an aquarium?

Picked up these rocks at a nearby lake, thinking they were some kind of slate. Now I'm not too sure.

What kind of rocks might these be? Are they safe for an aquarium? Im going to do the vinegar test and if they're safe I'll boil them, of course.

They're supposed to be for my 10g betta tank.

When wet they are a dark gray/black color

 

Never boil rocks. They can explode.

 

Never boil rocks. They can explode.

Lol really? I boil rocks every time I get new ones...

 

Lol really? I boil rocks every time I get new ones...

Your lucky lol I broke a window and got a nasty cut boiling one and I’ll never do it again.
Also you can test if it’s aquarium safe by using your nitrate #1 test bottle and put a drop on it. If it fizzes up then it will change your ph

 

It’s not so much the rocks themselves, it’s if there are any air pockets within the rocks then steam pressure can build causing the rocks to explode.
If you bring them to the boil very slowly that should allow any air to escape & lower the risk factor.

 

When I test to make sure rocks are safe, I first lick them a little to see if they’re salty (yeah yeah, gross, I know. Whatever. ) then I put them in a cup of water and add vinegar to the water. If it fizzes, it’s not safe. (Similar to the nitrate #1test, though I’ve never heard that before!)

 

It’s not so much the rocks themselves, it’s if there are any air pockets within the rocks then steam pressure can build causing the rocks to explode.
If you bring them to the boil very slowly that should allow any air to escape & lower the risk factor.

Key word here is "lower". Not "eliminate". Not worth the risk if you ask me.

 

When I test to make sure rocks are safe, I first lick them a little to see if they’re salty (yeah yeah, gross, I know. Whatever. ) then I put them in a cup of water and add vinegar to the water. If it fizzes, it’s not safe. (Similar to the nitrate #1test, though I’ve never heard that before!)

Aha, alright! So, i'll just do the vinegar test then

Thank you all for your replies! If I do a slow, gradual boil, is that ok? What else can i do to clean them?

 

Aha, alright! So, i'll just do the vinegar test then

Thank you all for your replies! If I do a slow, gradual boil, is that ok? What else can i do to clean them?

Like Coradee said, that would be the safest way if you're still planning to do a boil. But I personally don't like my chances of exploding a rock in my face really any higher than 0% if possible.

I sanitize rocks by soaking in a 5 gallon bucket with a solution of straight tap water and either rubbing alcohol or bleach. I use the alcohol myself but i just happen to have a lot on hand, bleach is cheaper. I'll soak them in that for like 3 days to a week. I'll then rinse them a good long time, and then soak for another week in dechlorinated water, changing 100% of it with clean dechlorinated water every day.

 

When I test to make sure rocks are safe, I first lick them a little to see if they’re salty (yeah yeah, gross, I know. Whatever. ) then I put them in a cup of water and add vinegar to the water. If it fizzes, it’s not safe. (Similar to the nitrate #1test, though I’ve never heard that before!)

Can't you skip the licking and go straight to the vinegar test, if you'll do it anyway? Not that anything is wrong with licking rocks.

 

I was told by the people at a local fish shop to scrub the rocks with ordinary soap and water, then rinse well, I followed this advice and have not had a problem

 

You can also clean the rock with a combination of vinegar and salt.

 

You can also clean the rock with a combination of vinegar and salt.

I never thought of that. But I like it.

 

I was told by the people at a local fish shop to scrub the rocks with ordinary soap and water, then rinse well, I followed this advice and have not had a problem

I would never clean anything with soap, then put it into any of my tanks. That stuff can leech into the water, and may not be good for some of the fish you keep.

 

Well I did rinse them very thoroughly ...

 

Can't you skip the licking and go straight to the vinegar test, if you'll do it anyway? Not that anything is wrong with licking rocks.

Ok I don’t care if you think there’s nothing wrong with licking rocks!! I ain’t doing it!!!

When I test to make sure rocks are safe, I first lick them a little to see if they’re salty (yeah yeah, gross, I know. Whatever. ) then I put them in a cup of water and add vinegar to the water. If it fizzes, it’s not safe. (Similar to the nitrate #1test, though I’ve never heard that before!)

Now do you lick them when you find them? Or do you wait till you get home to start licking? I mean people will move away from you if your walking down the beach licking rocks.

 

Ok I don’t care if you think there’s nothing wrong with licking rocks!! I ain’t doing it!!!

Now do you lick them when you find them? Or do you wait till you get home to start licking? I mean people will move away from you if your walking down the beach licking rocks.

I’m not a barbarian, I’d never lick rocks in public!!! Yeah okay maybe just a few times..... but no ones looking I swear

 

Hot water and a scrub brush. Its a rock. Nothing is all soaked in it.