I have a 4 stage Ro di system that I don't use you can have her for free if you pay for the shipping I'm happy to help came from Bulk Reef Supply it is practically brand-spanking-new only used it till what was in it did it came with was exhausted which is carbon sediment filter and DIY resin soon as this was gone I upgraded to 6 gauge so like I said practically brand-spanking-newno I don't have an RODI system trying to find one cheap.