try fish gravel or sand

[micker]

I am having the worst time trying to find growrocks, I was told to try fish gravel or sand, is there any other more readily available medium I could use instead and still get optimum results?

[Ron]

If you use gravel use the porous rocks you can find because they hold more oxygen than smooth stones. Some members use perlite because it's cheap but I haven't tried it yet. You also have to keep it from clogging the system because it's small by using paint strainers in the bottles.
Ron