RODI TDS high

theclownshow · Jun 11, 2026

I just got an RIDI system off Amazon. The TDS going in is around 240. When I installed it I flushed the filters without RO or DI per the instructions. I put the RO filter in and ran for about a half hour then installed the DI filter. I ran for about a half hour and the best I can do it 13 TDS. Any ideas?

I am thinking it could be a pressure problem. The presssure coming in is 40 which is on the low end of what it is supposed to be at.

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BryanM · Jun 11, 2026

I would be pretty suspect of the filter media in any import units like this. I cannot say if that is really what it is though.

A booster pump certainly is a good idea to get the pressure up to 60-65. The RO membrane will work more efficiently.

Randy Holmes-Farley · Jun 11, 2026

Can you Measure the tds after the membrane and before the di?

A Good Di alone can drop 240 ppm tds to zero, though it will deplete fast.

theclownshow · Jun 11, 2026

Randy Holmes-Farley said:
Can you Measure the tds after the membrane and before the di?

A Good Di alone can drop 240 ppm tds to zero, though it will deplete fast.

Actually I think with just the RO filter in it was running lower at 4-5 tds and went up to 14 when I added the DI