Does this require CO2 to grow and do well? I have a 32 gallon with 135W of
PC lighting, but as of yet no CO2. Guy at the LFS wanted to sell me some but
told me it wouldn't survive without CO2. Is this true? I don't mind if it
grows slowly, but if its true its gonna die then I will obviously pass on
it. Also, do you have to tie this down to something to keep it at the
bottom? Cause from what I've been told if you don't it floats to the top and
makes a mess. Any help is appreciated. Thanks.

Gord.