Rocks

[Clownface]

Is it safe to use rocks from fresh water streams/rivers?

 

[Double monti 61]

No!

 

[Arricefe]

Are you asking if the rocks will help with filtration straight from a stream? No. Is there a rock that you like and want to use in your tank because it looks cool? Or ?

 

[Clownface]

Are you asking if the rocks will help with filtration straight from a stream? No. Is there a rock that you like and want to use in your tank because it looks cool? Or ?

just curious. I haven’t researched filtration yet. Thanks.

 

[Big_Mclargehuge]

I'm pretty new to the hobby but rocks in a saltwater tank are part of the filtration. Go to the setting up a tank section on the sticky threads here. Good luck!

 

[Arricefe]

just curious. I haven’t researched filtration yet. Thanks.

Then as @Kristopher Sekely said, no. Rocks in a marine tank are used as part of the filtration. Bacterial will grow on the surface areas of the rock; the more porous the rock the more surface for the bacteria to grow. That’s a real simple explanation but that’s the basic idea.

 

[Difrano]

Then as @Kristopher Sekely said, no. Rocks in a marine tank are used as part of the filtration. Bacterial will grow on the surface areas of the rock; the more porous the rock the more surface for the bacteria to grow. That’s a real simple explanation but that’s the basic idea.

Bacteria also grows on freshwater rocks and part of the filtration system. But you can use freshwater rocks as filtration on saltwater tanks, is like adding dry rock.

 

[Arricefe]

Bacteria also grows on freshwater rocks and part of the filtration system. But you can use freshwater rocks as filtration on saltwater tanks, is like adding dry rock.

I asked the OP if he meant straight from a stream.

 

[Clownface]

I asked the OP if he meant straight from a stream.

yeah, there’s streams near where I live.thanks.

 

[Double monti 61]

Ok rocks contain different elements and it may be possible that you may contaminate your system with possible mineral and or biological elements that can inhibit growth in your tank.

 

[Fishbird]

I’m new to reef tanks but I do have a background in geology so I wouldn’t chance it with the rocks from the stream, unless you know with certainty what kind they are (and even then I might not chance it for reasons other than mineralogy) but anyway, the rocks used in reef tanks are made up of calcium carbonate, aragonite, CaCO3, and dolomite, CaMg(CO3). I’m sure occasional impurities make it into the limestone/rock but those three should be the bulk of it. Other kinds of rock can have any mineral known to science (and I suppose could also have a mineral unknown to science). A lot of slate, for example, had pyrite, or fools gold, in it. I would imagine that saltwater would make the pyrite (FeS2) eventually dissolve into the tank water and you might not want those elements in there. Then, pyrite often cooccurs with arsenopyrite (FeAsS) which means you could easily be putting a source of arsenic in your tank. Of course not all elements in all forms are easily bioavailable but the long and short of it is that that’s just two minerals that are common in a lot of rocks in streams around here. I think it makes sense to stick with limestone for a reef tank.