Suitable rocks

[darksheep]

hi

i need some advice on what types of rocks are suitable to put in a tropical fish tank, ive heard some rocks are supposed to kill the fish, and im not paying $6 a kg a rock from the pet shop, when i pick one up for nothing... that and i think half the fun would be getting something for free that and its quiet expensive seeing that the fish are bout 20 bucks each

That and when i get a suitable rock how do i clean it properly be4 putting in the tank

 

[Lateral Line]

Most "hard" rocks are silicates and generally quite safe to put in a tank. Anything that fizzes if you put acid, (vinegar for example), on it are Carbonates and can alter your water chemistry, quite drastically in some cases, (depends on your water). Any soft shale like stuff that feels "oily" should be avoided as it can contain a lot of organics. Obviously, you should avoid stuff with sharp edges. Finally, anything that feels "heavy" relative to its size is good to avoid, these are frequently ore minerals and can leach metals into your water.

I don't know where you are so can't comment on your local geology.

 

[darksheep]

thanks, for the info, local geology i live on the coast on the lower eyre penisula(South aust), are rock found nearly the sea (on the beach ok if the dont fizz with acid cause there are heaps of them and they have very nice features in them.. i need to rocks so i can build a coulpe of caves for my fish to hide in

 

[fatbobsufc]

i need to rocks so i can build a coulpe of caves for my fish to hide in

I bought a 25kg bag of "Scottish Cobbles" from my LFS for about £15. They are rounded cobbles made naturally from Granite which will not harm your fish. If you pile them up carefully (make sure they are well stacked so they don't fall) they naturally make caves and crevises of varying sizes for your fish to swim into. The best part is that they look very natural as far freshwater environments are concerned.

 

[Lateral Line]

>>> make sure they are well stacked so they don't fall

However careful you are, the fish will move things around, whilst vacuuming and claning, you will. Sooner or later you will wish you had used a blob of silicone sealant to build them structures.

Granite is ideal in a tank. Back of the beaches here is covered with it.

 

[darksheep]

um what kinda of silicone is good to put in a tank to glue rocks (sellys all clear ??)

 

[Lateral Line]

Use a sealant that is made for aquariums. Most non aquarium sealant contains a fungicide that is toxic in tanks.

 

[darksheep]

cheers thanks for the advice guys much appreited B)