RO, membrane.

[vanmo92]

My RO unit has gone through 2 membranes in less than 1 1/2 yrs. I do not think that the membraned I have been buying are any good. I have one of those Aquasafe RO units from eBay. Would this membrane fit in my unit and work?

 

[vanmo92]

oops, forgot the link:

http://www.aquariumwaterfilters.com...ategory_id=16&option=com_virtuemart&Itemid=26

 

[Gools]

Yes it will fit. And Dow Filmtec are the best membranes you can buy if you ask me. However I have seen them for alot cheaper, so you might want to search around

 

[o.c.d.]

The same membrane is cheaper at http://www.purelyh2o.com/product.php?productid=16216&cat=261&page=1
I ordered from them and their great also a RC sponser, most membranes are the same size just make sure the flow is correct. If it is wrong you can always use a add on membrane kit getting rid of yours (may be housing is the prob?) good luck

 

[HowardW]

I wouldn't get the 100 gpd one as it's not really a true membrane at all but a nano filter and only has a 90% rejection rate, as opposed to the 50 and 75 gpd membranes which have a 96-98% rejection rate.

 

[Buckeye Hydro]

What folks in this hobby call "stand size" is an "1812" membrane. The membrane you linked to will fit your system. As mentioned above, be aware that although this membrane produces a lot of water, it is not quite as clean as the water produced by the 50 and 75 gpd membranes. We also have a high rejection 150 gpd membrane if you have adequate line pressure.

Also note that if you change the capacity of the membrane in your system you'll need a new matched flow restrictor.

Why are you going through membranes so quickly? Have you changed the carbon block regularly?

What indication do you have that the membrane has gone bad?

Russ

 

[vanmo92]

I do change my filters regularly its been about 6-7 months. our well water is really not good at all, If I use it for my FW tanks, the fish do badly, if not die if its more than 10% WC or so. I get about 10-20 gallons of waste (used to get 50g) per gallon, but I put a restrictor on the waste line that slowed that to about 10:1.

THe only indication is that the water is coming out slowly about 13 hrs to get one gallon, and the TDS is near 100 out of the membrane. It climbed to about 70 a week after I got the membrane (changed the filters at the same time), and has been at 70 since. I think that it is the cheap membranes I have been buying.

I also have a booster pump that I bought from the same guy as I bought the unit from. I cant find the psi meter that I have, but when I checked last checked it was going crazy between 70 and 160 when I had the booster pump on, so I would like a membrane that can run on the 40-60 psi's that are supplied by our well instead of needing that pump, because I am pretty sure that 160psi is too high, but right now If I dont have the pump on then nothing comes out of the good water line.

This membrane that I am looking at says that it is rated at 50 psi. and out well ranges from 40-60. I have a 100GPD membrane now so I was thinking I should get another 100GPD one.

 

[Buckeye Hydro]

Let's back up a little.

First thing is that you need to get a flow restrictor that give you a 4:1 ratio at the pressure at which you run the system.

If the pump is giving you pressures that change from 70 to 160, something is wrong with the pump. It should give you a steady pressure. If you bought a decent pump it is adjustable. Adjust it to something less than 90 psi.

Get that pressure set, and then get your waste to permeate ratio set.... THEN check the performance of the membrane. You may find you don't need a new membrane.

Russ

 

[vanmo92]

It is not adjustable in any way. How do I find a 4:1 ratio with the flow restrictor? Where would I get a better flow restrictor?

 

[Buckeye Hydro]

We have flow restrictors intended to be used with 50, 75, 100, and 150 gpd membranes. we also have an adjustable flow restrictor for advanced users.

 

[vanmo92]

This one?

If so how would I install it?

 

[Buckeye Hydro]

It goes in the waste line, with the tail extending downstream, and the "pointed end" protruding from the tube.

Remove any other flow restrictors - use only one.

Will take you all of 90 seconds to install.

Russ

 

[vanmo92]

Alright. I will give that a try

 

[vanmo92]

one last question. If I were to buy a membrane from you guys, then would it last in storage for a year or so till I do need to replace my current membrane in case this restrictor does work out and fix my problem?

 

[Buckeye Hydro]

Yes.

 

[vanmo92]

Alright. Thanks.

 

[Gools]

Sorry to highjack your thread.
How does one figure out what kind of ratio I am getting from my unit?
I installed a 150gpd membrane, along with restrictor. TDS is at 0, everything is working fine. I am just surprised at how much waste water is being dumped down the drain, and want to know if my system is work at top performance. My water pressure is between 70- 75 psi. so all numbers seem to add up, jus wanted to know if there is an exact formula to tell performance.

 

[Buckeye Hydro]

Line up about 8 identical drinking water glasses in front of your system.

With the waste tube in one hand, and the DI tube in the other, in the time to takes you to fill one glass with DI water, how many glasses have you filled with waste water?

Russ

 

[AZDesertRat]

Your problem with the membranes failing is probably due to poor quality prefilters and carbons. The sole purpose of the prefilter is to protect the more expensive RO membrane. Buy the best prefilter you can afford and I guarantee your membrane will last longer and perform better.

Sounds like you need a pressure regulator for the booster pump too, set it at 80-90 psi and forget it.

 

[vanmo92]

Where would I get better pre-filters? Are the ones at melev's reef good quality? I am hoping that with this new membrane that I can just skip the booster. But I am not sure about that.