RO/DI unit issues- Maxcap 90 help

[RussellHill]

I have spectrapure Maxcap 90. Line in TDS is 58-59. TDS after membrane is 6-7. I have tried 2 replacement RO membranes from spectrapure. Put brand new RO membrane in yesterday and new DI filters. Flushed RO membrane before adding the DI filters. RO membrane is properly seated. Same readings as above but after making 40 gallons my first DI filter TDS out reading is 2 . Already 2 TDS after making only 40 gallons. Pressure is 55-60psi. I have the green restrictor on which is supposed to be 2:1. I tested the system and it is yielding 2.75:1. Feed water ph looks to be about 7. Any thoughts appreciated.

 

[RussellHill]

Update TDS out of first DI filter is now 3

 

[hkgar]

Something is very wrong. you should expect about 1 TDS and no greater than 3 after RO. The only think that pops out to me is a mismatch of restrictor to the GPD membrane rating. Generally rejection should be closer to 4 : 1

 

[azjohnny]

I agree something is very wrong. The feed TDS is low enough the OP could set the ratio @ 3/1.

I wonder if something is installed backwards

Russell Hill-
call or email Spectrapure they will get it figured out for you

 

[hkgar]

OP

Tap water to the sediment filter, then to carbon and then to the ro through the side with only 1 outlet port. Water exiting the RO is on the side with the dual outlets. The middle most outlet is clean water and the outermost is dirty water. the restrictor should be on the dirty water line. Clean water goes the DI canister.

Double check that in each instance the water is entering the canisters through the port labeled "IN".