One used Vertex Puratek Deluxe 4-Stage 100GPD RO System.

Notes:

1. Bought it used as a backup few years ago.
2. The pressure gauge makes a vibrating loud sound and the reading can’t be read clearly due to the vibration, but the booster pump is working.
3. The booster pump is not made by Vertex but a different made in China brand.
4. All the filters and the membrane had been replaced few months ago.
5. Make 5G RO water in about 50 minutes, that is just about 100GPD.
6. I like the fact that without power the unit won’t work, so you can add a timer to limit the damage if and when overflow occurs.