Pebbles and Rocks

[kev]

Hi,

I have heard people say that you should not add anything that has not been specifically designed for a fish tank. Is it not possible to clean (soak/boil) pebbles so they are clean. If not what do fish shops do to make sure that the items they sell do not contaminate tanks

Don't worry if you advise me not to try it I won't.

 

[SpEeDhOrN]

i put some large rocks from my garden into my tank after simply washing them in cold water a few times and they have been in my tank now for over a year and iv had no problems

 

[Lateral Line]

By far the largest majority of rocks/stones/pebbles whatever are quite safe to put in aquaria.

If a rock/stone/pebble fizzes when you put vinegar on it, that means it is calcareous and will harden your water and maybe raise your pH. That, however, may not be a problem in a rift tank for example.

Avoid pieces that are "heavier than they look like they should be". These are frequently but not always crystalline. Usually indicates it is some kind of metal ore which may poison your tank.

There are a few rock types that are high in organics and often throw a film on the surface - if that happens, take it out. It is usually not dangerous, but can interfere with the gas exchange at the surface.

Finally, avoid really sharp stuff.

 

[rosierabbit]

im not going to advise you not to try it, i'm just going to advise you not to take too much notice of what i say

i use normal stones out of my garden and stuff cos the stuff in my lfs (and probably many others) is very very expnsive. i probably dont clean it well enough either - i soak it in some aquarium water for a day or occasionally less. im sure there's a more suitable technique (like boiling it - people do that) but fish seem fine in my tank

 

[Kissifish]

I think somewhere on this site, someone recommended boiling the new rocks 3 times with clean water each time (discarding the boiled water, of course). And then after they cooled, pouring vinegar on them to see if they fizz.

 

[Alien Anna]

I had a look at the pebbles in my LPS (1 pound each) and they looked identical to the ones on the garden centre (5 pounds for a hundredweight). So I bought some pebbles from the garden centre and I've got them in all my tanks. Absolutely no problem. Some of the rocks have iron pyrites in them ("fools gold") but I looked that up and it actually seemed helpful to my plants, and not a problem for my fish.

Not that I'm saying you should copy me but I do wonder how on earth someone can justify charging 25p each for a small pebble!

P.S. I've glued the smaller ones together and made a nice cave, come filter stand (my Fluval filter keeps drifting down the side of my tank, which is annoying).

 

[Lateral Line]

>>> pyrites

Ordinary Iron Pyrites is relatively innocuos, simply FeS, Iron Sulphide. What are more problematic are things like Chalcopyrite, Sphalerite, Cassiterite, Blende, Torbenite, Galena etc. These can leach Copper, Tin, Zinc, Uranium and Lead respectively. There are many other minerals that outcrop naturally in England. Particulaly in the SW. Heavy, non-transparent crystaline ones tends to be ore minerals, and are best avoided. Transparent, or at least translucent minerals, tend to be silicates and hence inert. If in doubt - leave it out.

The original questioner is, however, from Basingstoke. I used to live about 15 miles away, (near Camberley). Most of the pebbles etc. you'll find locally are vatieties of quartz, (flint, jasper, chalcedony etc.). Totally inert and perfectly safe. It's worth checking with vinegar any larger pieces of rock, as there is chalk and thin limestones in the area.

 

[kev]

Thanks lateral line you really know your stuff.

I was thinking of the largish red pebbles from around weymouth (chesil beach) they have white strips through them. Is it iron that makes them red? is it toxic in a tank or is there anything else i should be causous of coming from a beach.

Cheers

 

[Lateral Line]

Are the red pebbles hard? If so, they are probably jasper or chalcedony. If they are hard and neither the red part or the white react to vinegar, they should be fine.

There is a softer red rock that outcrops along the Dorset coast, (the Keuper Marl bed from the Triassic period), which is very red, and has thin white calcite veins in it. If it seems softer than a normal "stone" or the white lines fizz, don't use it.

Iron is not a particulaly dangerous metal in the aquarium, as long as you don't go mad. Laterite is often added to planted tanks to improve the Iron content.

 

[bdktty67]

Oh my goodness!!!!

You all know so much. I have 3 rocks in my tank and now I don't know what to think because I don't know what they are or what they are made of. They might be harmful I don't know now. I don't want to go back to the LFS that I got them from. They have given me cause to doubt that they are'nt just in it for the money and could careless about helping newbies.

What should I do?

 

[Lateral Line]

The vast majority of rocks and stones, if clean, are perfectly safe in an aquarium. The basic advice has already been given in the thread. If they don't react with vinegar, are not suspiciously heavy or particulaly sharp, then they're probably fine.

 

[thebulk]

If you wash the pebbles in the same manner as you wash the gravel you get from the fish store they will be fine!

B)