"kush" wrote in message
...
I use three 2-liter bottles on my 75 gallon with 2.5 watts per gallon, one
on a powerhead and two into the canister filter. I'm usually behind on my
maintenance so, frankly, probably only two of them are fresh on any given
day. It does the job.

I suppose it's worth trying. Would a few 'tees' on the venturi on a
powerhead provide adequete dispersion? No canister, I use a wet/dry sump for
filtration.