Pure Blue H2O Stage 3 Membrane Replacement Filter

Good product, easy to use

We bought our unit 5 years ago from Costco and it’s still going strong. Great filtration system overall.

If yu want to maintain your own RO system you can't beat these filters and membrane cartridges. They are color coded and keyed so you can't accidentally put a cartridge in the wrong place.Each cartridge comes with new O-rings installed, so the chance of leaks is minimal.

I was a little concerned at first (about 2 weeks) because the faucet was making a lot of air-sucking noise but that ended and the RO system is functioning as new. This was the same noise that led me to replace the filter in the first place (approximately 2.5 years of use). Here's some numbers regarding the filtration: normal tap water 550 PPM; old filter(s) at time of replacement was 80 PPM; new filter (also replaced the the other 3 canisters with a Costco package) 30 PPM. 30 PPM was the best results I got when first installed the RO, so we're back to best it's ever done. I am happy with the results and do like this RO system. Much better than my old RO that would leak for days when installing new cartridges!

The product for whatever reason was not easy to install this time (2nd time replacing).After I took the entire manifold off I was able to get it lined up properly and then no problem. A few years ago, when I replaced the cartridge for the first time, I didn’t have any problem.Overall I like the system, water taste fine.

Finally, with modification of the Pure Blue, I can distance myself from proprietary culligan filters. The closest filter with rust is the culligan. The further filter is a modified Pure Blue. I used a paring knife to cut each filter. Another option is to cut the culligan manifold. After my mod removal and installation is simple.

The Stage 3 filter in our Pure Blue h2o reverse osmosis system was approx. 2 1/2 years old. This was the original Stage 3 filter that came with our system new. This filter is supposed to last 2-5 years. It's our understanding actual lifespan is dependent on ph level and water quality. We've been changing our Stage 1 & 2 filters every 6 months and the stage 4 filter every year as recommended.Our tap water (pre Pure Blue H2o reverse osmosis) reads 450ppm with our TDS meter---very hard water. Up to a few months ago, the water from our Pure Blue H2o reverse osmosis system would typically read 30-35ppm. It suddenly jumped up to 60-65ppm a few weeks ago. Installed a new stage 3 filter and the ppm level dropped down to 20ppm after the 60-65ppm water had a chance to cycle out of the reservoir tank. Pretty significant drop. Without the TDS meter we would have never known the Stage 3 filter needed changing.If you use the Pure Blue H2o reverse osmosis system, highly recommend purchasing a TDS meter ($15-$20 on Amazon) to accurately determine the best time to change the Stage 3 filter.

Our original membrane lasted more than 2 years with pretty constant use and maintenance. This was the best price we could find for replacement and its working just as expected. Simple twist-on installation, and you're good to go -- good that the other filters are easier on the pocketbook.