Need pump advise. What pump will run a ro/di filter?

[Delphinus]

As far as recirculating the waste water back through the RO/DI, I thought I read somewhere on RC of people putting a RO/DI on the waste water of one, and even another RO/DI on the wastewater of that one. Of course, that seems kinda costly.

As far as a low flow high pressure pump, there are such things and should run you about $100-200. The key to this style of pump is low flow, but can run pressure to about 80psi or even up to 200psi. People who have dart frogs sometimes use this kind of pump to produce a fog through fog emitters (you need very high pressure to get a good fog, otherwise the water droplets are just too big). At one point I knew a part number of a 200psi pump that you could get a Western Pump for about $160 but I've since lost the info since I never really followed through on my foray into that hobby. If you needed I could try to look it up but I'm not sure if this is the style of pump you're looking for.