Need some RO membrane help

[dwest]

Also, my incoming water TDS is similar to yours. My membranes typically last 3-5 years. I’ll replace mine when rejection gets down to about 95%. I use a Spectrapure system.

 

[Water Dog]

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[reefiniteasy]

I now get 2 out of the membrane. It just had to break in I guess. It is very efficient now.98.5% rejection. And TDS has been at 134ish since. So I’m happy.

 

[vjl501tech]

Have an membrane problem. Changed Aquafx 100gpd membrane
and the 3 other filters. now Water production really slow. Usually it would take 15-20 min per gallon, now it’s taking 40 plus mins. I’ve made about 5 gallons of water since the change and it’s still slow. TDS are reading zero.
I was wondering if the membrane needs some kind of breaking in period.
thank you for your help.

 

[Buckeye Hydro Verified Sponsor]

Suggest you call your vendor

 

[Snoopy 67]

The only other explanation would be an extra cold water supply, it kills production, when temps rise it will return.

 

[Buckeye Hydro Verified Sponsor]

Have an membrane problem. Changed Aquafx 100gpd membrane
and the 3 other filters. now Water production really slow. Usually it would take 15-20 min per gallon, now it’s taking 40 plus mins. I’ve made about 5 gallons of water since the change and it’s still slow. TDS are reading zero.
I was wondering if the membrane needs some kind of breaking in period.
thank you for your help.

100 gpd is equal to 0.7 gallons per minute or 4.2 gallons per hour. These are the numbers you can expect if your pressure and water temperature meet the factory spec.

If your water has less pressure or is colder, use our calculator to see what it should produce given those conditions.
https://www.buckeyehydro.com/calculator/

 

[vjl501tech]

Thx for all your responses. The last few days has been very cold here in NYC. Before that it was 50-60 degrees every day for weeks. Maybe it’s that.
I run the RODI at about 60 psi. I’m going to wait and see how it goes, then I’ll call Aquafx. I’ve had the RODI for 3 years and this is the first time I’ve changed the membrane. I don’t remember how slow or fast in was when I first used it.
thx.

 

[vjl501tech]

Hi all, need your input.
As I mentioned above since I changed the membrane on my aquafx barracuda it now takes 42 minutes to make a gallon of water as supposed
to the usual 17 or so minutes. I called Aquafx and the rep said its probably due to cold weather. He said to call if it continues when the weather
moderates. It has been cold here in NYC, but 42 min seems a lot. I run the unit at about 55-60 psi. I was wondering what The forum thinks about this.
thank you very much.

 

[Snoopy 67]

Entirely possible, my last 30gallon run took forever, temp is a bear.
My pressure is around 80PSI.

 

[Woodyman]

Hi all, need your input.
As I mentioned above since I changed the membrane on my aquafx barracuda it now takes 42 minutes to make a gallon of water as supposed
to the usual 17 or so minutes. I called Aquafx and the rep said its probably due to cold weather. He said to call if it continues when the weather
moderates. It has been cold here in NYC, but 42 min seems a lot. I run the unit at about 55-60 psi. I was wondering what The forum thinks about this.
thank you very much.

If you have a booster pump, increasing the pressure to 80-90psi would help with your production rate. If not consider getting one.

 

[vjl501tech]

Thanks all.

 

[Woodyman]

If you have a booster pump, increasing the pressure to 80-90psi would help with your production rate. If not consider getting one.

Just using a membrane manual I just pulled (Down FilmTec TW30-1812-100HR) at 60 PSI you should get ~120 GPD or ~19L per hour (2.3 gallons). Running that at the same temp and increasing the pressure to 80psi would give you ~170 GPD or ~27L per hour (7.1 gallons). That equates to ~208% increase in permeate production.

Temperature also plays a role in this as well, but regardless of temp, your permeate production will increase with increasing pressure.

 

[Woodyman]

Just using a membrane manual I just pulled (Down FilmTec TW30-1812-100HR) at 60 PSI you should get ~120 GPD or ~19L per hour (2.3 gallons). Running that at the same temp and increasing the pressure to 80psi would give you ~170 GPD or ~27L per hour (7.1 gallons). That equates to ~208% increase in permeate production.

Temperature also plays a role in this as well, but regardless of temp, your permeate production will increase with increasing pressure.

Now looking at temp, at 60°F you would see ~2.9 gallons per hour, at 70°F you would see ~3.7. thist equates to a ~27.6% increase in permeate production.