So that shower produces c02? If so that's a smart find! and thanks man I'd invest in one.companies are ripping people off with "grow room" co2 generators. If you compare these :
http://www.amazon.com/Eccotemp-L5-Portable-Tankless-Outdoor/dp/B000TXOJQ4/ $118
and
http://www.amazon.com/Hydro-Innovations-HydroGen-PRO-Generator/dp/B004JKDPKY/ref=sr_1_5?s=lawn-garden&ie=UTF8&qid=1423259417&sr=1-5 $345
They are the same unit internally, but they marked up the "grow" co2 generateor $220 lol
So, you can just get the one for $118 and it is all you need (same as the "grow") generator. Also you can take a hot shower!