Max Water ULP-4040 Reverse Osmosis 4" x 40" RO Membrane, 2600 GPD | ULP 4040 For Water Purification Desalination Commercial, Industrial, Agricultural | Compatible with Dow Filmtec AG4040FF, TW30-4040

Very good quality product.

Just replaced Hydronix BW-4040 membrane that went bad after about 2 years and 5 months. https://www.amazon.com/gp/customer-reviews/R16FWRWQBFE8GZ/ref=cm_cr_dp_d_rvw_ttl?ie=UTF8&ASIN=B01CFOGPXYInitial rejection rate is on par with the Hydronix, but the flow rate is much better. Both are rated at 2400 gal per day, but I could never get more than 1 gpm with Hydronix. This one is flowing at 1.6 gpm so far. Let see how long this one will last. Using in on my whole house well water RO filtration system.Fast delivery, good flow and good rejection rate.

These are great to use for helping improve the purity of water. It essentially helps purify the water down to 90 or 95% purity which is fantastic and it lasts you forever. We’ve only bought it this year so we don’t know how long it last but if you take good care of it, it should last a good five maybe seven years.

Works great..looks like quality stuff..very happy

The first time I used the pair of membranes, since I bought 2 of them to double water output, they worked great. My local municipal water has tds levels in the 500-750 ppm range with most days being in the 500-600 range. In the first month, my permeate ppm range was between 0-15 ppm at most, and didn’t use DI resin much to wash cars or my solar panels. Unfortunately, after 6 months of use, my permeate has steadily increased from the 0-15 ppm level to 80-95 ppm. It still removes about 80% of tds, but 20% leakage is already telling me that it’s time to replace what are lightly used membranes. I use a 20x4.5 sediment filter, and a 20x4.5 carbon block filter to ensure that no elements that can ruin these membranes get through. My usage is mostly for washing 1 or 2 cars, and periodic solar panel cleaning during the weekends, meaning that I use less than 100 gallons of permeate in each weekend event.Membranes are kept wet, and not used for drinking, even though I would feel comfortable drinking from them. Operating pressure ranges from 50 psi (municipal) to 120 psi via pump for pressure boosting when needing to increase water output.I didn’t think it would be fair for me to write a 1 or 2 star review without giving the seller a chance to respond first, privately through their website, but after 3 weeks, and no response from them, I believe that it’s fair to share my experience with anyone interested in considering this commercial RO membrane. I’ll be looking for a different manufacturer, even if I have to pay an extra $100 dollars for 2 membranes of the 4x40 size.By the way, the plastic end-caps cracked, even though I didn’t torque them much. The leaks are not from the circumference, but from the threaded fittings. I have replaced 8 caps at my own expense, and the last 4 are not leaking, but they required lots of teflon and a gentle hand to avoid cracking them. The cracks are almost not visible with the naked eye, but you’ll see the water leaking when pressurized, and they come from the threaded holes closes to the edge for the most part. I would suggest that it may be best to create a metal end cap. I’m sure it will be heavier and more expensive, but it will last a long time, and I care more about reliability than disposability. Unfortunately, plastic runs the risk of cracking each time the end caps are removed to service the membranes since the seals are tight. A metal end cap can take more punishment without cracking, and it’s a once and done deal.

The product arrived at an acceptable time, was the correct product and was installed in a matter of minutes. This corrected the gallons per minute regeneration.

Let me start by saying the stainless steel housing is well-made. The price point was very good. The stainless steel housing end caps suck. One of them came cracked. The seller was great at sending me a new one however that uncovered a bigger problem. I spent an entire Saturday putting together an RODI system only to find the end caps didn’t fit the membrane. The weird thing is the new end cap that the seller sent me to replace the broken one did fit. After a dozen phone calls and driving an hour and a half away I finally found someone that could sell me another endcap which fit perfectly. It was just really aggravating hitting this snag. I’m sure the seller would’ve sent me another endcap but I didn’t have time to wait again. Beware when you buy this the end caps may not fit your 4040 membrane. Huge headache.

Filters welll,.perfect,making good clean water for my whole house reverse osmosis system, thank you.