Rocks For The Aquarium

[Queen Bee]

I bought bags of rocks which look like big pebbles from Walmart and Dollarama. I found them in the craft section, and they were all different colours (very natural looking) Really liked the look and they were much cheaper than the LFS. Only $1 a bag.

Questioning now whether we should have spent the money and bought from the lsf. Both of us are having a reading of 6 or less in our tanks and our tap water reads 7.6. Starting thinking that the rocks may have limestone in them since testing my boyfriends water.

Does the lfs make sure there is no limestone in the gravel therefore safe for fish? Anyone know the rocks from Walmart I am talking about? I really like them, but have torn down both of my tanks for the 2nd time and am really being cautious this time around.

 

[rhostog]

Limestone would raise the pH of your water, not lower it.

The pH in the tank is often different from the tap water. There are various reasons, including carbon dioxide, rocks or sand, bogwood, and even your water conditioner may have an effect. Do you have soft water?

We've used pebbles we've found, washing and scrubbing them thoroughly in boiling water, leaving them to dry completely, and pH testing them. We started with the lemon juice/vinegar test, which was negative, but wanted to make sure, so put some water in two clean identical containers. Put the rock in one of them. Leave both for a couple of days (or more). Then test the pH of the water in the two samples. The reason for the second water-only control is that pH often does change if a container of water is left out - this makes sure you detect any change caused by the rock. We found two of our pebbles did have a slight effect raising the pH compared to the others and the control, so haven't used them.

 

[waterdrop]

Yes, people have reported problems with this before. Some of the members may be able to help you with the various tests that need to be done to the individual rocks that go into a tank. I think one of them is to drip vinegar and a given type of rock and see if it fizzes. Another test sometimes performed that is very effective is to place all the rocks in a deep bucket of tap water and test the water with your liquid-based aquarium test kits over several weeks to see how the pH and KH change.

There are several difficulties with getting a whole bunch of individually different large pebble size rocks from a non-LFS or non-aquarium-checked-out source, as you can imagine from the above. Its a lot of rocks to test out sometimes, and also, unless you have perhaps also some sandy-bottom areas in the tank, its often too bumpy a surface for catfish and other bottom dwellers of various sorts I think.

~~waterdrop~~

 

[Dave Spencer]

I`ve never bought a rock yet! Mother nature is much cheaper than your LFS. Most of my wood is what I have found, too.

I test my rocks with HCl acid at work. One of the test kits contains this acid in one of the bottles, but I can`t remember which. The rocks in the scapes below would have cost a fortune at a LFS.

This tank is a Juwel Lido which is 120l. This gives an idea of the size of rocks I used.

This is a 60l opti white taken on the day the tank was set up.

With a little common sense, and keeping your eyes open, there is no real reason to get ripped off buying hardscape material.

dave.

 

[waterdrop]

So, for a beginner, like I'm assuming Queen Bee is here, I think what Dave's saying is that if you find rocks out there in your yard or somewhere like that and you test them with an acid like HCl or vinegar and they fizz, then don't use them or they'll possibly raise your pH more than you want. If they don't fizz then most of them should be ok. (Dave can correct if I'm wrong, just trying to make the advice completely obvious.)

There may be some more lore on TFF about some minerals to avoid, but I've seen quite a few posts like Dave's that encourage people to just go for it.

~~waterdrop~~

 

[rhostog]

Found the topic about rocks - knew I'd seen it somewhere:

[topic="55806"]Rocks[/topic]

 

[waterdrop]

Found the topic about rocks - knew I'd seen it somewhere:

[topic="55806"]Rocks[/topic]

Great, yes! That's the one I was remembering, really good stuff.

 

[wendywc]

Those are probably river rocks if you bought them in the craft section. I picked up a huge tub of those from a garden center once. Those are safe. I sometimes use mine for a decorative rock pile on the sand and gravel.

 

[Queen Bee]

That is great news. I checked out the link to the rock post. Very well done and informative. I am going to use the vinegar test right now. That is actually something I always have and it's so easy. Thanks