Why would you want no bio media? Bio media is great - it cures all the invisible toxic waste like ammonia and nitrite that a mechanical filter doesn't deal with. If you're not treating these wastes biologically, then you'll just have to keep changing the water.
What size pond are you planning on building? Like SpotsMama said, bio media really helps in the long run in keeping your tank steady. If it's a really large pond, I'd reccomend the new Fluval FX5. That canister filter is a beast and it even has a built in computer chip. It's rated for 400 gallons!
The filters designed for ponds are about the same price or only somewhat more expensive than a big canister filter. So far as I know they always use bio media.
The Skippies are biological filters that are so simple they can be homemade and are very inexpensive. Skippies can be built to handle ponds with thousands of gallons of water.
Posted: Sun Dec 10, 2006 5:16 pm Is it nessesary?
