Subject: Biowheel

Greg Tong wrote:

> All biological filters do what a biowheel would do so everyone s
> your reasoning, get better plant growth by removing their bio
> filters--canister, sponge, biowheel, UGF.

I don't think anyone has said that you get better growth without 
extra biological filtration.  I think most people suggest that 
extra biological filtration is not necessary on a prudently 
stocked planted aquarium.  IMO, The biggest benefit to keeping the 
biological filtration down in a planted tank is that if the plants 
use the ammonium before it is converted, it prevents the build-up 
of nitrate in the water, and lessens the likelihood of algae 

> When you removed the biowheel, did you also stop the waterfall? 
> splashing is likely to dissipate more CO2. By stopping the water
> keep more CO2 in the water for the plants. Was the biowheel your
> change?

I used to think so too.  Then I did some measurements on a tank 
with and without the biowheel.  The amount of CO2 loss was 
negligible, and easily replaced when using supplemental CO2 even 
from a yeast reactor.

My feeling at this point is that biowheels in a planted tank are 
in the same position as carbon in a planted tank.  They are an 
added expense, and  there may be very slight advantages to _not_ 
using them, but they are easily compensated for if you really feel 
the need to use them.

Karen Randall
Aquatic Gardeners Assoc.
Boston, MA