Try AQUAFINE, Valancia, CA. http://www.aquafineuv.com/COMPANY/News.htm

I have the model SP-1 which was originally 220 vac but I changed it over to
110 vac for a couple bucks. I'm using it on my 8 gph but it's suppose to
hand my unit when I upgrade to 24 gph. So it comes close to your
requirements. (never did know what the upper capacity limit was).

Steve
s/v Good Intentions