Eating Up RO Membranes

[Woodyman]

And my TDS after the DI just climbed to 6
I changed it yesterday and made 60 gallons of RO/DI

yea with ~100 TDS going into the DI your going to kill your DI quick!

It seems like at one point you weren't having any issues with your setup, has anything changed other than the actual filters as you replaced them?

 

[flyfisher2]

 

[flyfisher2]

I’ll pull it out and dissect it

 

[flyfisher2]

yea with ~100 TDS going into the DI your going to kill your DI quick!

It seems like at one point you weren't having any issues with your setup, has anything changed other than the actual filters as you replaced them?

nothing other than three months of usage.

 

[flyfisher2]

I put fresh sediment and carbon block in yesterday after the rise in TDS. Is the reading after those filters too high?

 

[Brew12]

Lots of good advice so far. I would agree that temperature is the most likely cause. We get pretty hot here in northern Alabama and I ran my system outside for several years before recently bringing it in. I don't see any need to bring it in but you do need to mitigate the temperature issue. The first thing I would do is provide some shade for the unit. Once you have water flowing through it, the sun will be less of an issue, but if it is sitting stagnant the sun can damage the membrane quickly. And as others have mentioned, flush the supply water long enough to get the temperature in the hose to drop. My outdoor hose gets morning sun, so if I am going to make RODI in the morning I run water for just long enough to get the hot water out of the hose.

I'm hoping you've already done it, but the other thing I would check is to make sure you have all the interconnecting tubing hooked up properly. I've seen issues where people have bypassed filters by not connecting the hoses in the proper locations.

 

[laverda]

The sediment and carbon blocks typically have very little affect on your TDS. It really depends on the particular size of what's in your water?

 

[flyfisher2]

 

[Woodyman]

I put fresh sediment and carbon block in yesterday after the rise in TDS. Is the reading after those filters too high?

no, my TDS is much higher going in, the sediment and carbon really don't remove much if any TDS typically, at least not in any measurable quantity. They are there mainly to protect and prolong the life of your RO membrane.

 

[Woodyman]

nothing other than three months of usage.

gotcha, in that case my assumption would be heat and possibly still chlorine. I know you checked it, yesterday, but something to keep in mind is that at times more chlorine is used to treat municipal water. So while you may typically see lower numbers there is always the chance that one day when you were using it the chlorine was 3x or even 4x then what it normally is and chlorine got to the RO.

 

[flyfisher2]

I posted the pics of the opened membrane this is the one I was using up until now.

 

[Woodyman]

Doesn't seem like you found any carbon deposits. and it doesn't appear you had any melting either.

 

[Woodyman]

how were the O rings on the membrane? all in good shape without any tears or cracks?

 

[flyfisher2]

gotcha, in that case my assumption would be heat and possibly still chlorine. I know you checked it, yesterday, but something to keep in mind is that at times more chlorine is used to treat municipal water. So while you may typically see lower numbers there is always the chance that one day when you were using it the chlorine was 3x or even 4x then what it normally is and chlorine got to the RO.

Understood but what can I do about that if that’s the case?
I run two chlorine blocks. Both are three months old

 

[flyfisher2]

how were the O rings on the membrane? all in good shape without any tears or cracks?

 

[Woodyman]

Understood but what can I do about that if that’s the case?
I run two chlorine blocks. Both are three months old

If you have already taken the time to swap filters, and plan on putting in another new RO membrane, my suggestion would be to move the unit inside and monitor. The other thing would be to get a more precise chlorine test kit and swap out the carbon as needed instead of on a schedule (every 3 months, 2 months, etc.) The same goes for your sediment. It sounds like you use your unit regularly so you may need to replace sooner than you currently are for sediment and carbon.

How much water to waste do you get from your unit?

 

[flyfisher2]

 

[Woodyman]

Rings appear fine, still a chance your housing has warped from the heat overtime and that could be leading to bypass as well.

 

[flyfisher2]

If you have already taken the time to swap filters, and plan on putting in another new RO membrane, my suggestion would be to move the unit inside and monitor. The other thing would be to get a more precise chlorine test kit and swap out the carbon as needed instead of on a schedule (every 3 months, 2 months, etc.) The same goes for your sediment. It sounds like you use your unit regularly so you may need to replace sooner than you currently are for sediment and carbon.

How much water to waste do you get from your unit?

Haven’t measured it to be honest

 

[Woodyman]

Haven’t measured it to be honest

gotcha, I was just curious. For example if your at a 1:5 RO to waste your using 6 gallons of water just to get 1 usable gallon. So if your producing 60 gallons a week your pumping ~ 360 gallons of water through your first 4 stages of sediment and carbon every week, so depending on the carbon filter your using it may only be rated for 1,000 gallons. In which case you should be swapping carbon about every 3 weeks.