Changing my ro membrane

[mook1178]

How do I know when to change the RO membrane? Is it finished to carbon, just make a schedule and stick to it? What is the typical life?

 

[gkprevite]

I change my ro membrane yearly. Some people change it less often but it depends on use. If your starting to see your tds creep up it might be time to change

 

[towels]

Following. I have not yet had to change a RO membrane - only DI - which I know changes colors

Mine went bad after only a month or so of use and possibly 200gallons of output. Pretty sure it was because my pressure was insane at first

 

[mook1178]

I change my ro membrane yearly. Some people change it less often but it depends on use. If your starting to see your tds creep up it might be time to change

I have DI resin as well. So should I take samples every now and then from before the water goes through the DI?

 

[gkprevite]

Yes. You should be reading after the to membrane and before the di. If you have too many tds after ro I will cause your di to be exhausted quicker.

 

[mook1178]

That does make sense when I read it. Thanks

 

[Reef.]

check what the tds is after the membrane but before the resin, it needs to be less then 96% rejection, so if your tap tds is 300 your tds after membrane needs to be less than 12, if more, then you need a new membrane or less likely your water pressure is not high enough.

 

[theMeat]

Membrane should have 96-97% rejection. If you have 100 ppm before the membrane it should be 3 or 4 ppm after. If you’re getting less than the recommended rejection rate it’s time to change. If your rejection rate is good changing it is a waste

 

[mook1178]

That info about 96% rejection is great to have. Thank you!

 

[JTP424]

Drop in a 3 step TDS meter, you can gauge the various filters and it will give you a good idea on when to change them.

 

[BryanM]

You can install an in-line TDS meter. When mine reads 1 I buy replacement stuff. When it hits 2 I replace stuff :)

 

[reeferKen]

This video helped me out on that question, hope this helps.

 

[gbroadbridge]

How do I know when to change the RO membrane? Is it finished to carbon, just make a schedule and stick to it? What is the typical life?

I have a dual TDS meter that measures the TDS into the membrane and again afterwards.

I aim for less than 5% of the input TDS coming out.
At the moment I see 90 ppm going in and 2 ppm coming out which means the membrane is still okay.

FWIW, my membrane is 9 years old and has never been changed.

I also measure TDS after the DI stage, when that increases from 0 to 1 it is time to change the DI resin.
The carbon filter is changed every 12 months.

 

[Merge_595]

https://a.co/d/b9BXETYI change mines every 4 months faithfully..overkill probably so..Just another thing I don't have to worry about..

 

[Salty_Northerner]

I just changed mine last month and its almost 2 years old and honestly It could've gone another 2 years from the look of it. oh well at least I have a good idea when it needs to be changed now. I back flush it 3-5 min after use and probably why its lasted so long.

 

[Reef.]

That info about 96% rejection is great to have. Thank you!

Some are 98%, if you pull it out it should be written on the label.

Just to be clear, that method is only good for the membrane not carbon, the only reliable way for carbon is time used or amount of rodi made.

 

[Thuan]

I change my dual membranes every 6 mos.

 

[Reef.]

I change my dual membranes every 6 mos.

They last years.

 

[Thuan]

They last years.

I don't let it go that far. Every 6 mos, right on schedule

 

[Reef.]

I don't let it go that far. Every 6 mos, right on schedule

How often you change your carbon?