Cool, thanks for posting cyberlocc. I think I am going to use this to build a chameleon reservoir filler filter, and then hook it up to my sink and use that to fill the bucket. It currently takes me hours since I have to wait for my PUR system to filter water at over an hour per gallon
So that portable one, is cheap. However its also going to be slow, if you want fast (depends how many cages your misting obviously) your going to want to look at better RO systems.
Bulk Reef Supply, sells RO units with Double Filter setups. This is good from 2 points, for 1 it doubles the speed you make water, so the base cheapest model is like 75 gallons per day, so it will make 75 gallons of water in 24 hours, so about 3 gallons an hour. However if you get the upgrade kit, it will process 6 gallons an hour, also the way they work also reduces the waste water. So normally waste water is about 1:3-5 to 1 ratio, with the double ROs its 1:1-2, so you waste less water as well.
Its also easier on your filters, so while you have 2, they dont need to be replaced that often, and usually the RO membrane only need replaced 1 time per year or 2 anyway. So a little bit more upfront, but will make up for it over time, in less waste and and the filters, cancel out pretty much.
Having a non pressurized storage tank, also reduces waste water BTW, so if you have a reservoir that is large, and free with a float and a stop, then filling that to stop doesn't waste as much as the Storage tanks do.