RO unit issue

[Ron Sower]

....Awhile back I replaced a membrane in my RO Buddy system that puts out 50 gallons in 24 hours with a TDS of 50+/-...somewhere along the way it had started producing  50 gallons in about 8 hours ...the finished product had measured about 350 TDS, as compared to 25 TDS before when it was doing 24 hours production of 50 gallons....

...so after I moved here, I set it up again and put in a new membrane, in January I believe...it started out producing 25 TDS in 24 hours...
...after my water change this past Saturday, I noticed that the barrel was full in 8-9 hours...I tested the water and it was at 100 TDS...

...all the stuff I've read has said the membranes should last up to a year...

...any ideas or thoughts on this?...

[LizStreithorst]

Did you replace your carbon filter at the same time.  Nothing will kill a membrane faster than chlorine.  I don't think that carbon takes care of cloromine but if it doesn't that might be the problem if it's added to your water.

If you've done everything I would contact the manufacturer and ask them for help.

[Ron Sower]

...my tests show no chlorine in our tap water...but I don't know about chloramine...I will check on that....

[LizStreithorst]

Another thought.  Do you know what your water pressure is.  RO units generally need between 40 and 80 PSI.  If you have higher than that I'm not sure what would happen.

[Ron Sower]

...it's 60 psi...

[LizStreithorst]

I'm at a loss, Ron.  I'm not an expert with these things by any means.

You may try joining Simply and asking there.  Lots of folks there are more familiar with how they work than I am.

[Ron Sower]

I'm at a loss, Ron.  I'm not an expert with these things by any means.

You may try joining Simply and asking there.  Lots of folks there are more familiar with how they work than I am.

[Babers]

What I’ve read is you have to use the same rating membrane when you replace them. If it’s 100gpd, you have to get 100 gpd membrane, otherwise you’ll get different water parameters. What’s the technical explanation...idk 

[Ron Sower]

What I’ve read is you have to use the same rating membrane when you replace them. If it’s 100gpd, you have to get 100 gpd membrane, otherwise you’ll get different water parameters. What’s the technical explanation...idk 

...hey that actually makes sense in an odd way to me...thanks, Joel

[LizStreithorst]

Are you sure, Joel?  I've read that I can increase the product water water my increase the GPD rating of the membrane.  I bought a unit rated for 75 GPD and asked the guy that if I needed more RO I can't I just go up to a 100 GPD membrane and he said yes.  This is a small company that builds it units to order at no charge so I doubt that he was just giving me a line.  I don't know what would happen if you were using a lower GPD rated membrane.

[Babers]

Here’s the discussion I’ve read about the membrane. I guess it has to match the flow restrictor too of the unit.

http://www.reefcentral.com/forums/showthread.php?t=1890806

Maybe your guys know better since that’s their specialty. Did they say if it changes your water parameters if you change your membrane to a different one?

[LizStreithorst]

That I didn't ask.

[Babers]

Technically, they told you the truth. You can change your membrane to whatever amount per day of RO you want....but your water parameters will change with it, I think. Also depends on your water pressure if you can produce that amount.