Yes, but it's expensive if you buy it in those 2# BBQ bags. Go to the landscaping/garden dept and buy rough textured rock. It's not so much "Lava" rock as a rock with lots of texture or surface area.

Lava rock works as bio-media, but there are other things that work just as well and are so much easier to handle and to clean. Try bird netting! You know the stuff....it's black plastic netting used to keep deer and birds out of the garden. Simply wad it up really tightly in the filter and there is plenty of surface area for beneficial bacteria to grow on. When it's time to clean it, it is not nearly as hard to handle.

there are a few things better than lava rock.lava rock cloggs too much.a better bio would be ceramic rock or bio balls

Thanks all for your respond. Bird netting sounds interesting. One more question. How thick the bird netting. I remember seeing really thin plastic net (a little bigger than hair net) and a pretty thick net use as fence on construction. Which one to be correct? Thanks

It's not that thin stuff that you toss over trees....it's more like deer fense only with smaller holes. Not that heavy construction plastic fencing. The holes are maybe 1" square or so. It is light weight enough that you can bunch it up tight and get a lot of it in a filter. The wads can be easily removed and rinsed off.

Here is a link that might be useful: bird netting

Why don't you try nylon pot scrubbies in dryer bags? You can buy everything at a dollar store. You might have to hit two because you will clean out their stock of scrubbies.

How many pounds required of lava rock in 1100 gallon pond.
Thank you