New RO Membrane

[jerthunter]

Awhile back there were several threads concerning a particular type of RO unit that was sold on the big auction site. The name on the unit is Dvoneb and it is supposed to be a 125 gpd unit. There was a lot of talk about it but what I am interested in is if it is possible to swap the 125 gpd membrane out with a 100 gpd membrane and if so where could I purchase it? The reason I ask is this. The unit puts out far too little. No where close to the rated output. From what I understand the membrane used in this unit is rated at 125 gpd but is supposed to be used at high pressures. Supposedly there was a 100 gpd membrane that was designed for normal household pressure that was the exact same size.
I'm sorry if I am confusing right now but if anyone can help with this it would be greatly appreciated...
Thanks

 

[jerthunter]

Or can anyone direct me to somewhere I can find out actual specs & sizes of actual RO membranes. I've been searching and all I can find is people trying to sell them.

 

[acrylic51]

You can swap the membranes of the unit......If you check good online places that deal RO units you should be able to find what your looking for......I can't mention names......The thing you want to look for is DowTec membranes and don't settle for less......The bigger you go in gpd you'll sacrifice water quality to a point......Usually anything over 75gpd has a lower rejection rate as far as the membrane.....Somewhere between 90-93% rejection which IMO is rather poor, but if you stay around 75gpd or lower you'll see rejection rates of 98-99%.
Ultimately you really don't need a 100gpd or 125gpd unit.......If you preplan you always have water on hand.......

 

[jerthunter]

I don't need anywhere near 125 gpd or 100 gpd but what I am getting right now is horrible. I purchased the unit because it was fairly inexpensive. I just want to make sure I can just swap membranes. I have read that if you change the gpd of the membrane you also have to change the flow restricter, is this correct? Also would a 75 gpd membrane fit in place in the same housing I already have? Thanks

 

[jerthunter]

Well I sure hope the new membrane works. I can't stand getting 5 gpd from a unit that is supposed to give me 125 gpd.... Anyone else have a problem like this?

 

[birdy]

Are you sure the problem isn't the water pressure at your house?
They sell meters that will read the pressure and if it is not high enough you can buy a booster pump that will increase the water pressure through the unit.
and yes you should probably change the flow restrictor to match the membrane.

 

[jerthunter]

The water pressure is SOME of the problem but there is some or reason... As far as the flow restricter can those be found at a hardware store or should I look at a place that deals in ro units? The place I found the membranes doesn't sell any flow restricters

 

[acrylic51]

If you change to a smaller gpd membrane you will have to change the flow restrictor without a doubt.....Anyone who sells you the membrane will or should ask you what your running currently.......You might want to check out AirWaterIce or Custom Aquatics for prices on membranes and such and they both carry the flow restrictors.....I honestly don't think you'll find them at a hardware store though

 

[jerthunter]

Thanks for all the information. I did some research and it appears that my RO unit is using a flow restricter for a 50 gpd membrane. Oh well, I am going to change the membrane anyways and a too small restricter doesn't explain why I am getting too little water but it is a problem that I am glad I found..

 

[bang guy]

cold water will also slow the flow through the membrane.

 

[jerthunter]

There isn't much I can do about the water temp. I ordered a new membrane and I hope it helps. While reseaching this problem I found other forums where people had this same problem with the exact same unit and it was the membrane.

 

[drewwpb]

I see you are in Ohio, another place to keep in mind for your RO supplies is buckeyefieldsupply.com.

 

[jerthunter]

Originally Posted by drewwpb
I see you are in Ohio, another place to keep in mind for your RO supplies is buckeyefieldsupply.com.
Cool thanks, I will check it out

 

[jerthunter]

nice site btw, wish I had seen it before I ordered my new membrane but I will definately keep it in mind for my future water needs.

 

[jerthunter]

Well I just got done putting a new membrane in my RO unit and WOW! It makes water!!! I still have to give it time but so far it is 100 times better then the membrane I had before... Just a note to anyone wanting a RO unit, you might want to stay away from ones claiming 125 gpd because I am pretty certain the 125 gpd membranes you get require much higher pressures....