How do I wash rocks to put in my aquarium?

[bettafishlover86]

I have some smooth rocks I found outside that I want to put in my betta fish tank. How can I wash them to ensure they are aquarium safe?

 

[xxBarneyxx]

Where about's outside? Is it somewhere they may have come into contacts with pesticides or other chemicals? For example from a field? If this is the case I would consider not using them. If you really insist I would soak them for several weeks in a large bucket of water and change the water out daily to try and remove any chemicals that they may have come in contact with.

If it is unlikely to have had any exposure to chemicals I would just put in boiling hot water and give it a good scrub with a brush.

The other thing to watch out for is what type of rock is it? Some rock will alter the PH and hardness of the water. A quick a basic test is to drop a bit of vinegar on them. If it fizzes then don't use it. If there is no reaction then its probably fine.

 

[WhistlingBadger]

Barney's right on. Things to consider:
1. Where is it. If it's in an agricultural area or next to a road, I would be very reluctant to use.
2. What kind of rock is it? Give it the vinegar test; if it fizzes, it probably is no good for anything other than livebearers or cichlids. I always run my rocks by a geologist friend if I don't know what they are.
3. Clean it up. If it's from a stream, boil it, bake it in the sun for a week or two, and/or give it a very thorough going-over with a stiff scrub brush to remove any aquatic critters that might be hitchhiking. I usually do the latter two.

 

[Byron]

Be careful about boiling or baking rocks. There are reports of the rock exploding.

I have river rock in my tanks, purchased for 75 cents for a 5-gallon pail of the rocks I selected from the landscape supply. River rock is granite which is safe so far as being inert (won't affect GH, KH or pH). And occurring from rivers where they have been for centuries, they are safe. I rinse them off under the tap, maybe use a brush for dirt.