New RO Membrane Releasing 111 PPM!

Hello AZDesertRat,

I will try that method of flushing and check the membrane and get back to you.

I measured the rate of flow at 60 psi and it was less than one gallon an hour.


Wiley
Horicon WI

 

I believe you said you had a flush kit, its not open is it? All the water should be going through the flow restrictor not bypassing it.
The filters have been flushed all they are going to be at this point and any dust, glues or binders are lodged in the next filter downstream, you will not be able to flush it away. Thats not really you problem here though, its something with the membrane not the filters.
What is your water temperature? One gallon per hour is very slow and cold water could be part of that.

 

Hello AZDesertRat,


When I conducted the flush my flush valve was open to avoid the flow restrictor.
The temperature of the water entering the unit is approximately 59° F.
Also, my TDS post-DI is now in the eighties.



Wiley
Horicon WI

 

please tell us your filter setup again#1 pre filter,#2 carbon block, and so on

 

The filter flush is done with the line between the cabon block and the RO membrane disconnected so you don't get any preservatives, carbon dust or binders on the membrane. When you flush the membrane the flush vaolve should be closed so the wate rpasses through the membrane and not around the membrane so it pulls the preservatives out of the membrane completely and not just off its outside surface.

59 degree water will knock a 75 GPD membrane down to 53 GPD at 50 psi, at 60 psi it would be 65 GPD and at 70 psi it would be 77 GPD still at the same 59 degrees F. If you added a booster pump at 90 psi it would increase the GPD to 102 GPD and improve the rejection rate or removal efficiency a percentage point or two which would increase the DI resin life between 50 and 100%.

Still need to get the poor membrane performance sorted out first though.

 

The Water leaving your membrane should be 5 TDs at the most before your DI filter. Chances are You have something hooked up wrong. Your system should have proper instructions for replacing your filters, We have a complete page that we send out with every filter replacement. Email me several pictures of your system, I can trouble shoot your system in minutes. I am the owner of purelyh2o.com, Your system was copied,not very well, from the system I designed many years ago.We have sold over 48,000 RO/DI FILTER SYSTEMS in the last 11 years. Email me if you are still having problems!
[email protected]

 

Dear AZDesertRat,


Thus far a damaged membrane is suspect. I've been in both phone and email contact with BRS and they have been very helpful. After a few emails, a short phone call, and a few pictures BRS has now shipped a replacement membrane and a DI resin refill. Thus far I am pleased as I understand membranes do get damaged from time to time during shipment.

Assuming that replacing this membrane will resolve my issue of high TDS readings post-membrane my next question for you, if you would so indulge me, if my tap water is 185 TDS, I am running a PSI of 70, water temperature of 59 degrees F, what sort of reduction of TDS should I expect? The reason I ask is because while running the flush as you requested without the membrane and resin in place I realized a TDS reading of 185. This remained the case for ten gallons approximately fifteen minutes. Would the lack of flow restriction affect the ability of the sediment, one, five micron and two carbon blocks that much?






Wiley
Horicon WI

 

A new 75 GPD Dow Filmtec RO membrane should give you a rejection rate of 96 to 98%. It should also give you 77 GPD flow rate. If your tap water TDS is 185 you should be seeing a RO only TDS between 4 and 8 at most, I would expect closer to the 4 TDS.

If you don't get that you might consider one of Spectrapures Select series specially treated, hand tested and guaranteed membranes that will give you better than 98% rejection rate, my personal system is doing 99.35% still after 3.5 years. For the $45 including a matched flow restrictor you can't go wrong and it only takes a couple DI resin replacements to pay for it.

Again the sediment filter and carbons have very little to no effect on TDS, they remove large suspended solids larger than 1 micron, dissolved solids or TDS are in the 0.0001 micron range.

 

Dear AZDesertRat,



My new membrane and resin came in the mail today and after an hour I'm still getting 53 TDS after the membrane. I noticed the new membrane had a longer connection stem a bit of a turn and it dropped in but didn't pop or click in any further. Should I half to twist it back to lock it in? What am I missing here? I don't want to replace resin every third day. Is this a fault of membrane installation or just another DOW membrane that doesn't meet even its 96% standard?




Sincerely,

Wiley
Horicon WI






WWPIV

 

Your membrane housing may have a hairline crack you cannot see but opens up under pressure.

When I talk to the folks at Spectrapure they tell me they fail more membranes then they pass during their bench testing process. Granted they are looking for 98+% rejection rate but they say they found the average off the shelf membrane is in the high 96% range when they sell in less demanding systems like for horticulture and drinking water.
If you have not tried it, get some silicone grease available at Lowes and HD or any homebrewing shop and is used to lube the O rings on kegs and beer lines. Rub a very fine coating of the grease on the O rings and sealing surfaces of the membrane and see if it inserts better and further. Other than that maybe some photos would help us troubleshoot the problem.