[scleractinian]

Dosing pump, diaphragm type, reatively high flow (IIRC, up to 25+ GPD, uses 1/2 tubing in/out). Adjustable frequency (speed) and stroke (volume/stroke). Connector for external (PC, via RS232 IIRC) control, but can run stand alone using onboard controls. It also appears that you could rig a low voltage trigger (such as a float switch). Comes w/ instructions. Used, but works fine. Should be great for topping off w/ kalk (or just R/O) on even large systems, for dosing nutrient solutions or suspended plankton, etc.

Make offer, or see at Midwest Marine tomorrow (I'll put my MR Username on my name tag).