RO/DI and TDS readings

[tonkaoz]

unless Im missing something I looked at your pics and that's just an ro unit no di Is that correct ?

 

[woochi]

unless Im missing something I looked at your pics and that's just an ro unit no di Is that correct ?

The two stages before aquarium on diagram is the di stages

 

[AZDesertRat]

I think he my be talking about the photo in post #23 which is RO only.

 

[Buckeye Hydro]

I like to keep my water super clean so once i get a reading of 1 or 2 tds i swap out all filters, tds only measures tds not specifically what it is. They could be ammonia phosphates silicates list goes on, now I've heard of people stretching it up to 5-10. Im considering getting a second di chamber paired with the spectra pure max cap resin. A fellow reefer told me with that he has replaced them for a year and a half and still reading 0 tds!

A reading of 2 on your DI water really tells you nothing about the need to change your sediment, carbon, or other prefilters.

Russ

 

[Buckeye Hydro]

By adding all those stages in front of the RO you have actually made things much worse, not better. Each filter, housing and fitting has an associated headloss or pressure drop which reduces the RO rejection rate or removal efficiency. You want One sediment filter in the 0.2, 0.3, 0.5 or no larger than 1.0 micron range. One, no more, One 0.5 or 0.6 solid extruded carbon block, the RO membrane and either one or two DI filters. Thats it, no more and no less.

Right on the money. The OP has one of the worse cases of "more stages=better filtration" disease I've seen!

Russ

 

[Buckeye Hydro]

If you are running your RO with water that is chronically (for example months at a time) colder than 77F, do yourself a favor and check your waste water to purified water ratio. If you are getting more than a 4:1, spend $4 and get yourself a different flow restrictor. With a proper flow restrictor you will be close to a 4:1, have higher pressure at the membrane, faster water production, and marginally more pure water from the RO (=longer resin life).

We've set many customers up with two flow restrictors - one for the summer time, and one for the winter when tap water temperatures are low.

Restrictors are very inexpensive and take all of about 30 seconds to change.

Russ