RO/DI help

[orthokardia]

I have an older aquasafe 5 stage RO/DI system. I replaced all three prefilters and the membrane with BRS filters. I have made about 200 gal of water and have exhausted two DI recharges. The TDS levels are 68 from the tap, 68 after the prefilters, and 22 after the membrane. I am currently without DI, but the post DI TDS was 2 before exhaustion. What is up??

-bart

 

[poolkeeper1]

I would check your TDS Meter against another one, If that one is correct you have filters that are doing nothing! I had the same problem with filters i bought from another bargain online source. Once i replaced them with quality filters the issue went away. BRS has good filters and SpectraPure has IMO the best.
Are you using a hand held or inline meter?
Bill

 

[Pickupman66]

Sounds like a bad DI cartridge or it didn't seat properly

 

[poolkeeper1]

That's possible, But the Pre filters are not removing anything and they are before the Membrane! I'll put my money on a bad meter or Crappy filters.
Bill

 

[orthokardia]

I did a poor mans cal with store bought rodi and read 0 to 1 TDS so I think the meter is close if not dead on. Should I expect more that a few hundred gal from BRS prefilters? I am guessing that caused the early exhaustion of the DI resien. I assumed the membrane would still clean the water, but would clog faster and the water production would be for crap.

 

[orthokardia]

BTW the BRS filters are the six stage deluxe replacement kit and the dow filmtec 75gpd membrane. they were installed early july this yr (three months ago).

 

[poolkeeper1]

Bart, All those factors depend on how bad your water is entering the unit, But most pre filters last around six months. If your water is very bad you could have burned the filters that fast, Also I never had good results with the Filmtec 75 gpd membrane and now use the Spectra Pure 90 gpd one. Also you need to check that you have the proper flow restrictor for that membrane. If your not getting 4 to 1 waste to good water the unit is not working correctly. You can check that by measuring the waste to good water in a couple of measuring containers and start them at the same time and stop when the first one reaches the desired level, Then the other should be at the other level 4 to 1
Bill

 

[orthokardia]

thanks Bill.....as always a wealth of knowledge.
I am using the BRS recommended restrictor for the membrane (550), but I will double check the ratio. Does 4:1 hold for all input pressures?

 

[Pickupman66]

Bart, 4:1 should hold for all input pressures from my experience.

 

[poolkeeper1]

The optimal pressure is 70 psi @ 4 to 1 ratio, Other pressures work but will degrade the membrane quicker. Usually a decrease in the amount of water being made in a 24 hr period would indicate a faulty unit (Something Wrong) I had the same type problems with mine a while back and Mel helped me understand how to get one back to peak performance. It requires installing Valves in place of the flow restrictor, a valve on the good water side, and one for regulating pressure. Then you adjust them all until you have the 4 to 1 ratio @ 70 psi. If you need more info just give me a call it's easier to explain in person.
Bill

 

[orthokardia]

Thanks Pickupman.

and for Bill....correct as usual....I got to looking and found that I had replaced the 550 flow restrictor with an old bypass 500 that allowed for flushing the membrane to flush my membrane. of course I had forgot to replace it with the 550 before making water. I replaced the 550 and am back down to 2ppm of TDS. welllllll off to buy more DI refills.