Is it safe to use beach rocks in a freshwater aquarium?

[MurfQ]

I would of course boil them, but I'm wondering if it might be impossible to clean the salt from them and if that might cause a problem. Any advice?

Also, how long should one boil rocks before putting them in an aquarium?

 

[JDogg]

boil them, scrub them, do the acid test, and unless you know your rocks and can id it i would post it here so someone can tell you if they think it will leach anything bad into your tank

 

[MurfQ]

Don't know the rocks. They are a reddish coloured rock. I can get some pics and post them. Was also thinking of using a little slate if it would be safe.

What do you mean by do the acid test?

 

[evercl92]

Scrape or break the rock, so that some part of the surface is now missing. Put a small amount of an acid (most people use viegar, but I prefer household cleaners, for a more dramatic effect) on the rock. If it fizzes, it will likely dissolve in your tank (it's most likely a carbonate based rock), thus you shouldn't use it. If you do use a household cleaner, make sure it's an acid, such as hydrochloric, phosphoric, etc, as some are basic, ie bleach. We can certianly take a stab at the type of rock, if you are able to post a pic.

 

[JDogg]

i know my rocks rather well, so please do post a pic....

off the top of my head, many "red" rocks might contain iron, i not all so an id would be good...

slate, if cleaned well, should be great for in your tank

stronger acids like muric (hydrochloric) will also react if there are metals in the rock...

 

[hc8719]

if the beach is salt water, i'd say no

 

[newfound77951]

Beach rocks, if they are the proper type of rock, are fine. I have several basalt and granitic cobbles in two of my FW tanks that I got from the saltwater beach in front of my office. I scrubbed mine and then baked them in the oven at 250F for an hour. Baking or boiling will kill anything living, and washing them will remove any salt traces.

 

[Sicklid]

IF they pass the vinegar fizz test, just wash them off w/ a scrub brush or a quick soak in bleach followed by a rinse and soak in what ALL OF US have laying around: DECHLORINATOR.
Boiling/Baking/Blah blah blah is unneccessary... It's a ROCK, guys. Some rocks can explode from baking, but I think 250F should be safe for an hour like Newfound said. Anyway another thing nobody here has mentioned is the Freshwater to Saltwater switcheroo (and vice versa).
The bad things that live in one environment usually rely on that environments osmotic pressure to survive. Thats why we treat ich with salt, cause the bad guys get squashed by the weight of the salt waters' pressure on their little hides... So, technically, baddies from a salt water rock when placed in fresh water will have less resistance on themselves from the outside and will explode and croak.

 

[newfound77951]

Boiling/Baking/Blah blah blah is unneccessary

Not always....I took some rocks from the same beach, gave them a scrub and put them in a 5 gallon....two weeks later I had insane white fuzz growing everywhere, and I couldn't get rid of it. Bake or boil them just to be safe! Some critters are quite tenacious and can withstand extended periods of drying or osmotic shock. 250F should not damage any rocks that are otherwise safe to put in your fishtank. I have seen some beach cobbles crack under a bonfire but that fire also melted aluminum and therefore was at least 600C or about 1200F!

 

[7Enigma]

IF they pass the vinegar fizz test, just wash them off w/ a scrub brush or a quick soak in bleach followed by a rinse and soak in what ALL OF US have laying around: DECHLORINATOR.
Boiling/Baking/Blah blah blah is unneccessary... It's a ROCK, guys. Some rocks can explode from baking, but I think 250F should be safe for an hour like Newfound said. Anyway another thing nobody here has mentioned is the Freshwater to Saltwater switcheroo (and vice versa).
The bad things that live in one environment usually rely on that environments osmotic pressure to survive. Thats why we treat ich with salt, cause the bad guys get squashed by the weight of the salt waters' pressure on their little hides... So, technically, baddies from a salt water rock when placed in fresh water will have less resistance on themselves from the outside and will explode and croak.

The problem with this theory is that rocks are porous, they will readily absorb some amount of water and if that water contains chlorine, if not boiled, even after adding dechlor, it could leech chlorine into the tank killing the fish.

I would also recommend AGAINST baking a large rock because as mentioned they most definately can explode as the liquid inside turns to steam and escapes......quickly..

 

[MurfQ]

Ok, sorry for the long delay, but here a couple of pics of the rocks in question:

The darker spots on the first photo are wet spots on the rocks. Obviously, this is the look I will get in the aquarium if it turns out to be safe to use them. I haven't done the acid test yet but will definitely do that.

So, anybody know what type of rocks these are and whether or not they would leach anything into my tank?

 

[newfound77951]

Those look like either basalt (if they are blackish) or quartzite (if purplish which is how they look in the pictures). Either way they will be just fine in your tank. You can try the acid test if you want but I don't think it's necessary with those rocks, plus you'll have a heck of a time trying to break off a piece anyway! Boil them or bake them (your choice) and put 'em in!

I think the group of uniformly colored rocks will look nice.

 

[MurfQ]

Yeah, I was thinking it would be awfully hard to break them, but I figured I could at least chip them with a hammer and chisel. They are purplish. The colour in the pics is quite accurate (thanks to my whibal card ) I think they'll look great in the tank as well. I could go to pets unlimited and purchase beach rocks for $25 dollars that in my opinion don't look half as nice as these, but I figured that'd be like flushing my money down the toilet if these would be safe. I've been trying to figure a nice use for these rocks anyway because they're too nice looking to not use for something. I originally gathered them for use in my garden, but have since gone a different route with that.