Driftwood, Rocks And Shells (real)

[Shara]

I have a 10g freshwater tank but was wondering if I can put naturally tumbled (smooth) shells or rocks in the tank? Or driftwood if it's all been sterilized? What are the rules??

 

[drobbyb]

I have a 10g freshwater tank but was wondering if I can put naturally tumbled (smooth) shells or rocks in the tank? Or driftwood if it's all been sterilized? What are the rules??

Such things can be added to tanks. However the driftwood and the shells will have an effect on pH (opposite effects respectively.) The shells will raise the pH and the driftwood will lower pH.