What RO Membrane

[3mm3]

I'm using the 75 gallon a day Dow filmtech and cant take it anymore. Its nearly 3 months old and I'm getting only 1 gallon per day maybe 2 max. My tds going in is only 40 and coming out is 0. The pressure sits at 55-57psi.

I am wondering what you all use for a membrane and what its performance is. Also if you run a boost pump on the system. I currently don't run a boost pump because I was assured my pressure was optimal for my membrane.

 

[m and m]

Could one of your filters be clogged?

 

[SmokeyCFH]

I've got a BRS 75gpd, it takes about 2 hours to fill a 5g container and I'm using:

• 75 GPD Dow Filmtec Membrane
• Purtrex 5 micron depth sediment filter
• MATRIKX CTO/2 5 micron carbon block
• MATRIKX+1 0.6 micron carbon block

That's with around 40 in and 0 out.


75 GPD RO/DI 5 Stage Standard System - English

 

[MBG75]

I'm using the 75 gallon a day Dow filmtech and cant take it anymore. Its nearly 3 months old and I'm getting only 1 gallon per day maybe 2 max. My tds going in is only 40 and coming out is 0. The pressure sits at 55-57psi.

I am wondering what you all use for a membrane and what its performance is. Also if you run a boost pump on the system. I currently don't run a boost pump because I was assured my pressure was optimal for my membrane.

There are only like 2 companies that make membranes and Dow is the most common.
U have something going on. I know there was a bad batch of carbon block filters going around.

 

[SmokeyCFH]

perhaps flush it..

 

[AZDesertRat]

OK, lets start with the basics.

What is your tap water pressure?
Water temperature? You are not trying to blend hot and cold water are you or have never ever used hot water I hope?
How is the system plumbed? Is it on a faucet adapter, self tapping saddle valve, ??? Where does the waste line go to and is it open discharge free of any backpressure?
Do you know for sure you even have a flow restrictor in the waste line?
What is your exact measured waste ratio not what they claim it should be? Use a measuring cup and a clock or watch and time and measure the waste for exactly one minute then do the same with the treated flow. It should be very close to 4:1 waste to good.
Have you tried removing the sediment and crbon filters one at a time and making water to see if one or more is plugged or fouled?
Do you have a flush kit on the system and is the flush valve in the open position? Either way, throw the flush kit out the window, they are worthless and only lighten your wallet.
Do you have an autoshutoff valve and if so what is it hooked to as in a float valve etc?

Did the system ever make a decent amount of water?
Do you have any photos so we can make sure it is plumbed correctly?

The Dow is the most popular membrane on the market and is probably not your problem but the above should give us an indication.

 

[3mm3]

Thanks for all the input and ideas. I had been lost for the last 2 months. It all began 2 months ago when I installed new prefilters along with new membrane and new auto shut off valve. I had assumed that I had a bad membrane. The flow was bad from the start and I made calls thinking I recieved a bad membrane but those calls got nowhere. You guys got me thinking. Thank you.
You all helped me find the issue and its something easy I had not thought of for some reason. Pressure going to system 55-57psi. Pressure after sediment filter 55. Pressure after both first and second carbon block filter 6psi...... 6psi was all the membrane was seeing. I ran to the hardware store and local pet shop and got the prefilters replaced. Ro system now works like a champ. puts out pretty much what its rated for at 0 tds. As for the filters i was running i will not purchase those again.
Thanks a bunch

 

[MBG75]

Thanks for all the input and ideas. I had been lost for the last 2 months. It all began 2 months ago when I installed new prefilters along with new membrane and new auto shut off valve. I had assumed that I had a bad membrane. The flow was bad from the start and I made calls thinking I recieved a bad membrane but those calls got nowhere. You guys got me thinking. Thank you.
You all helped me find the issue and its something easy I had not thought of for some reason. Pressure going to system 55-57psi. Pressure after sediment filter 55. Pressure after both first and second carbon block filter 6psi...... 6psi was all the membrane was seeing. I ran to the hardware store and local pet shop and got the prefilters replaced. Ro system now works like a champ. puts out pretty much what its rated for at 0 tds. As for the filters i was running i will not purchase those again.
Thanks a bunch

So u had one of the bad carbon block?

 

[3mm3]

So u had one of the bad carbon block?

I cant confirm I had one of the known bad filters but mine definitely where garbage. They where apparently bad from the start. Im going to call the company tomorrow and see what they have to say.