R/O Membrace

[thinhvu]

When is it a time to change R/O membace? I have 4 stage R/O - DI Spectrapure which comes with a detector to check water quanlity. So far I change sediment and carbon filter at the interval of 6 month and D/I once a year. I have never change R/O membace. The system has been running for 18 months. Your opinion would be appreciated.


Thanks

 

[thinhvu]

^^^^^^

 

[O P Ing]

hi.
If you change the prefilter regularly (seems like you do), the membrane will last quite a long time. They should last longer than your DI, for example. Check the rejection ratio to see if the membrane is ruined by sediment or bacteria. Also check the conductivity of the output to make sure the membrane is not leaking. You can use the dector to guestimate the conductivity... it is done by setting the little switches inside the case...

If either test failed, it is time to replace the membrane. To be safe, call the manufacture about the replacement interval. Spectrapure is one of the more respectable company out there, and you can take their words. If you have a DI after the membrane, only major problem with a bad membrane is a short DI life.

 

[ReefLion]

I've heard varying numbers from sixth months to two years. If you use color-change DI and kinda keep track of it, you can tell when it's going through the DI faster and change then. In any case, I really try not to go more than one year.

Tim

 

[newkie]

Assuming a 4-stage: replace sediment/carbon, remove DI, test water coming from membrane. If > 20-30tds its not functioning too well. I just replaced mine, it was reading 87! After DI it was 57. Now I'm back to 0. Talk to Brian from aquatic reef systems (see powerbuys), he'll help you figure it out.

 

[bowfront]

I've got a Spectrapure 5 stage and changed the RO membrane at about the 3 year mark. I have the red light/green light Spectrapure meter but I don't trust mine. Tank started going south a while back and the meter was still showing green. I invested in a TDS meter and found out that my DI was long gone. Do yourself a favor and pick up a TDS meter and take out the guess work. Time is really irrelavent its how much water you are processing.

 

[reefland]

The black push button testers can be taken apart. They have DIP switches on the inside to set how sensitive you want the unit.

The best bet is to get a TDS meter. Test your TAP water, test the RO water, should be 98% or better rejection for the typical quality membrane. After DI should be 0.

 

[thinhvu]

What is TDS test? Online Store and brand?


How do you determine the D/I color change?

 

[SPC]

http://www.aquaticreefsystems.com/TDS_Meters.htm
Steve