I had been planning this for quite sometime. I wanted a watercooling system that sat outside the PC and was capable of cooling more than 3 PCs with one pump. I first chose a reliable pump:
Custom SeaLife Velocity Silent Aquarium Pump
The worlds quietest and only titanium centrifugal pumps. Designed for all saltwater applications.
2 year no-fault warranty on manufacturer defects
ultra-quiet (less than 30 db)
"Dry Run Cutout" with thermal switch for added safety
noryl housings and impeller
titanium or stainless rotor and separating wall
ceramic bearing ball carbon graphite bearing cap and EPDM O-ring
Rated for temperatures to 140° F and line pressures to 50 psi
1/15th horsepower, 140 Watts, 1.3 Amps
Equipped with mounting bracket, and 18/3 SJTWA 6' power cord
The Velocity T4 Pressure Pump is rated at 1225 gph @ 3' or 240 gph @ 17' and comes with 1" hosebarb inlet/outlet.
(Yes, it's expensive. I'm not suggesting this to anyone else, it's a baby to me...most all the kids are out of the house )]
Next I chose 3 (for now as it's manifolded for more inlets and outlets) Black Ice Xtreme Radiators rated at 3134BTU per hour with Panaflo 120mm High Speed. Model FBA12G12H rated at:
2500 RPM fan speed
103.8 CFM air flow
41.5 dBA noise level
Power Consumption: 7.2W
I used high pressure 1/2" braided high flex hose throughout and connected the PC's with a rather ingenious all plastic full close snap fittings to facilitate removal of PC from loop connected by 3/8" high pressure clear coiled air service hoses.
Some pics of it being constructed in my garage: