http://www.roultratec.com/company.asp
they don't list there prices online anymore but give them a call It will
be well worth your time. I just ordered new filters for my 5 stage 100gpd
and I think it was around $40
Sorry I forgot to mention that this is a shot of the right side of my tank
that is in the process of being setup.
After some looking around about moon light's I found Fabio's website
http://www.kaotica.com/frag/diy/moonlight/
I made a few modifications but the principle is the same.