Amethsyst in tanks?!?!

[dixaisy930]

Can you use amethyst and/or agate geodes those pretty rocks that look plain on the outside but have the "crystals" inside aquarium (aside from the sharp edges)?

And what about seashells? I was told they change the pH.

 

[NinjaSmurf]

I've used quartz crystals in my tank before, and I think someone said it's okay to use geodes, you just have to watch out for really sharp points on them so they don't hurt your fish.

 

[susangc]

Seashells (calcium carbonate) change the hardness of the water as they dissolve, eventually affecting the pH.

Amethyst is quartz (Silicon dioxide -- glasslike) which is probably okay. To be sure, drop a little vinegar on a sample. If it fizzes, your rock will be a problem. (In the case of a geode, I would check several spots if it looks like there are different minerals represented.)

Good luck!
Susan

 

[Rusty_S]

Just a quick question, I've heard of this vinegar testing method a few times over the last few days, and it might be a stupid question but why does the rock fizzing mean you can't use it?

 

[vantgE]

rock fizzing means that the rock will raise ph and is only suitible for aquriums that require lower{EDIT-9should be->)Higher} ph which is pretty much all of them except rift lake and marine

 

[Rusty_S]

But an acidic rock would lower the pH to make it more acidic, unless you meant the rock was alkaline, vinegar is acidic so the fizzing may mean it's reacting with an alkali in the rock, if that is what you meant But I'm not sure that is what you meant.

 

[vantgE]

maybe i said it wrong but if it fizzes you can only use it in a rift lake or marine tank

 

[Rusty_S]

Yeah I think I know what you mean, probably alkaline if it reacts with the vinegar. Thanks for clearing that one up for me though vantgE

 

[bunjiweb]

If the rock fizzes it is carbon based i.e. limestone and is reacting with the alkali as Rusty says.... meaning you cannot use it in the tank as it will raise the hardness and the ph of your water.

This is why you must always use hard carbonate rocks like granite that don't dissolve at all in water.

Ben

 

[Max Action]

I have some limestone in mine to balance out the bogwood. Hmmm.