Yes a pet store. Cats and goldfish love to eat lightweight volcanic rock. Home depot, lowes, Wal Mart, Ace, or any other store with a garden department will have it.
careful though, all ive seen at the mentioned stores recently has been MG perlite, its finely granulated, and has been soaked in MG ferts..... not a winner in my book hopefully with spring approaching and such, the selection of stock will increase. hopefully
this is my first hydro grow so im gonna ask a potentially dumb question...... will fish tank rocks work inplace of rock wool or pearlite?
perlite and rockwool are not the same thing so No fish tank rocks wont work. You can find perlite at any garden/nursery store...rockwool prob there too or find a local hydro shop and go there. What kind of hydro set up you planning on running? _numb_