Ok I went and looked and I did not remove the restrictor. There was quite a bit of confusion when I purchased this unit. So I can't quite remember all that went on. It wasn't supposed to be sold as it was a prototype and was supposed to be for in store use only. I'll try to speak with Albert tomoro and see what he recommends. I would prefer the Vertex membrane but I have never seen any for sale until Tyler mentioned it in an earlier post. Thanks for all the suggestions

It's unlikely that you will find a 'Vertex' membrane. Vertex, Aquasafe, BRS, Buckeye Hydro & most of the other names you see on RODI units are companies/vendors that assemble the systems from standard, generic components. In our case, that means 10 inch cartridge housings for all your prefilters as well as a standard size RO membrane housing. Apart from that, the only difference is what options each vendor provides for what price. Auto flush, pressure gauge, TDS meter etc. Most of these are 'standard' components as well, sourced from other companies that specialize in their manufacture. I recall seeing one vendor/'brand' out there that individually tests each membrane before selling the system, but you pay for that in final price & to be honest, I'm not sure it's worth it. It's still a DOW membrane.

It's kind of like large appliances. In reality there are only a few actual manufacturers out there and companies like Sears, GE, Whirlpool etc. simply have them built with their own logo, a few cosmetic changes to differentiate them from the competition and on to the showroom floor they go. I'd wager the compressor in every refrigerator out there, regardless of brand name, comes from across the pond to the east.

Quite certain the DOW filmtec membrane is pretty much the standard these days & it's what you'll find in most good quality RO systems, Vertex included. Might be another manufacturer, maybe even two, but they're up against a giant with DOW & unlikely they have the R&D department, let alone the manufacturing might at their disposal to provide meaningful competition.

Yea that all makes sense Mike. And i've never seen a vertex membrane. I replace the membrane every year and I go thru the same thing each time. For the life of me I can never remember which membrane to get. As I said before this was a prototype I was sold so no box or instructions etc. The first time I changed this membrane the one I took out was a 50gpd membrane. I seen that someone posted about getting a vertex membrane and that added more confusion. Note to self....never buy prototype equipment or stuff from fly by night stores.:lol:

Actualy there are about 5 major membrane manufactures and a few smaller ones, Dow was the standard, could be still, I haven't looked at specks laitly, but most of the RO's we buy don't come with DOW as they are more expensive. actualy there are a lot more than 5 now, just looked it up, here is a company that sells a tone of different brands
http://espwaterproducts.com/resident...-membranes.htm

most companies will buy a generic 60/100 membrane and sell there unit as a 100gpd. well this system will put out 100 gal per day but only at 90 PSI water pressure and the right temp, at the test rate of 60 psi it is only a 60 gpd membrane. always but the membrane that will give you your desired output at 60 psi, unless you have a booster pump.

my RO came with two membranes, they were hydrotec 50gpd membraines, when they were done I replaced them with 100/160 membranes and bought a booster pump that would give me 120 PSI feed psi. I ended up getting 300 GPD out of this set up with cold water, there is a lot you can do just decide what you want and get the right parts. you can also use a flow valve as a restrictor, just takes a bit to set it up but it is more fine tunable, I used to set my system at 3.5/1 rejection rate.

Steve

should be getting way more than 1 year from a membrane, how are you determining it needs changing? Are you flushing it, is your waste ratio okay?

Nothing wrong with buying a prototype, as long as you're willing to do a little research & sort the issues out, which is generally not a problem with an RODI system. There's a lot of experience on this site and much of the research has been done by someone already. Witness the fact that I've been corrected on my manufacturer's musings by Steve (StirCrazy). I had no idea there was that much competition banging at DOW's door with respect to RO membranes. In this case, I am guilty of not doing sufficient research before presenting my info!

+1 on this, my 75 gpd membane is still the original since I first started the system new in April 2009. So that's 5 years & it still gets my TDS down to 0 in the winter & 1 in the summer (source water TDS is around 165). I ordered a new membrane over a year ago & it's still in the original packaging, waiting to be installed. (Shelf life is probably TX'd, anyone need a 75 gpd membrane?)

I'd say that source TDS & how one runs their system can have a large impact on RO membrane life. In my experience, running the RODI system for a minimum production of 6 gallons has paid off. Most of the time after 6 gallons of RO, I make an additional 7-14 gallons of RODI. Manual flush for a few minutes before & after production is important as well IMO. I would never plumb it into a sump for automatic top offs where the system only runs for short bursts of a few minutes or less. Well, maybe on the west coast where the source TDS is below 10, you can pull that off without too much harm done. Otherwise, the product water never reaches the lowest TDS since the membrane will not have a chance to get properly flushed.

Thanks for the link to the SpectraPure maintenance/info sheet Mark. Great info & I've incorporated the RODI production formula into my fish tank Excel spreadsheet. Incoming water temperature around here varies from 8 Celsius during cold months, to 15 Celsius in late summer. I can't even get close to the 25 Celsius used to rate my 75 gpd membrane. I do well for pressure though, at 91 psi before the membrane. Plugging 8C & 91psi into the formula, the expected gpd for me is 65.75 gpd. Not sure I'm going to mess with my restrictor. I believe mine is incorporated into the manual bypass/flush valve & I don't think it's trimmable like the one on the SpectraPure. In any case, it seems I'm getting close enough to the desired 4:1 ratio & obviously my membrane is liking it, 'cause it's still the original.

That was my big issue when I received this RO unit. I didn't buy a prototype when I purchased this over the phone. I got hosed. It was supposed to be brand new.

That's what I was just thinking.

Paul should be in all day tomorrow, i can have them in stock for tuesday