Replacing an RO membrane

[dnjan]

I think I finally have to replace my RO membrane. Output has dropped off significantly. I have a Ultralife Reef Products Crystal Clear RO filter that I bought back in 1999, and I also have a replacement membrane that I bought a year or two later (when I read that membranes need to be replaced every year or two).

Couple of questions:

Will the unopened membrane still be OK?

What all is involved in replacing the membrane?

Thanks!

 

[reedman]

I would think if it's still sealed you have no worries.

It's a simple process to replace. Remove the canister, remove the old one, install the new one, waste a bit of water flushing the new one...good to go.

 

[dnjan]

Well, I replaced the membrane yesterday, and gave it over an hour break-in. It is now producing water even slower than the old RO membrane. Any suggestions???

 

[Brenden]

Are you sure the GPH rating on the membrane was as high as the original?

 

[-=dieseldave=-]

They usually take a hundred or so gallons untill they are broken in. Do you have pressure gage on the RO housing? If so is the pressure around what it usually is? Did you replace your pre filters as well? If they are clogged the membrane won’t produce at optimal rates either.

 

[dnjan]

GPH rating is the same.
No pressure gage, but there have been no changes which would affect the input pressure.
I replaced the carbon filter, but not the particle prefilter (before the carbon).

What is confusing is that the RO-production is significantly slower than it was before I replaced the carbon and the RO-membrane. I went from about 1/2 gal in an hour to about 1/2 gal in 4 hours. (this is a 25gpd membrane).

 

[reedman]

Has your waste water increased? Could be that your old membrane was ripped or damaged and allowing the water to pass by instead of through.

Do you have a TDS meter? You could check the TDS to see if it is significantly lower than it was before. Could be the filter is just working better than the old one.

I can't think of anything else that would cause a large drop in production.

 

[dnjan]

I can't really tell the wastwater output easily - it is piped outside to a rosebush and some other plants.

Anyway, I rinsed off the old RO cylinder and re-installed it. Water is coming out at about the normal rate (approx a gal/hr) and the TDS is 1.

So, on the good side, I have RO water again. On the bad side, I am clueless as to why the replacement membrane didn't produce.