Ok here's the deal, I have a Kent Hi-S 35 gph 4 stage unit, I changed out all of the filters Excluding the RO membrane, which should last about 3 or 5 years, My water here is very clean for tap but I changed them out at 6 months even with a TDS reading of 0 about two months into the new filters, recently it just slowed down, almost instantly. I still have good water pressure, I removed the line before the DI from the RO & I seem to get good flow To the DI unit, so I'm wondering if either the RO or DI may of just gone bad, got stopped up or whatever. The flow restrictor is also working fine, I took it out & it is clear. I do need more water, I was thinking of up-grading to a 100 gph but I need to find out my problem first, I may also need a new DI cartridge. So any ideas would be helpful, thanks!