What is more effective for Reverse Osmosis
The Ultra-filtration/Reverse Osmosis process alone is not without its shortcomings. It is simply ineffective in removing the lighter, low molecular weight volatile organics such as THM's, TCE, vinyl chloride, carbon tetrachloride, etc. They are too small to be removed by the straining action of the ultra-filtration ability of the membrane and their chemical structure is such that they are not repelled by the membrane surface. Since these are some of the most toxic of the chemical contaminants found in tap water, it is important they by removed by a carbon filter added to the RO system. In fact, nothing could be better for effective carbon filter absorption than having an RO membrane prior to it to remove practically all of the contaminants which would gradually impair the carbon's performance. To address this situation, nearly all reverse osmosis systems built for the home incorporate a series of filters that include one or more carbon filters.

Reverse Osmosis Membrane Rejection Guide

Higher Performance RO membranes Begin With Shorter Leaves

All spiral-wound reverse osmosis membranes are comprised of membrane "leaves" —individual sheets of membrane through which feed water passes and is purified. Short-leaf design is an advantage because less pressure is required to deliver water to the end of each leaf, and more uniform flux is maintained from one end of the leaf to the other. To give an example, APEC's FILMTEC membranes are fabricated with up to twice as many leaves and each leaf is 1/3 to 2/3 shorter than those in other membranes. The result is a highly efficient membrane —one that provides purer drinking water and a longer life. Besides overall system designs and parts used, this is the reason why different ROs have different contaminant rejection capabilities.

Flow Rate of Reverse Osmosis Systems

All reverse osmosis systems are rated (and priced) by their flow rates (Gallons of Pure Water Produces Per Day). The effectiveness and productivity of RO systems increase with greater water pressure and temperature. The actual flow rate (in GPD) of any reverse osmosis system depends on your home water pressure and temperature. This is why all of our systems are named as they are, for example: 36/45 GPD means it is rated at 36 GPD at 50 psi of water pressure, 45 GPD at 60 psi. While the industry standard* is set at 60 psi, we know that not everyone's cold water is at 60 psi and 77 degrees F. Instead of misleading customers into thinking that a 45 GPD system will guarantee a flow rate of 45 GPD, we remind you that you might get less than 45 GPD —perhaps 36 GPD or even less if your pressure and temperature are very low! So when flow rate is critical for you, you need to consider all these factors.

*Please note that the industry standard is not necessarily followed by all vendors. We have seen other RO systems claiming 100 GPD at 100 psi —very unrealistic input water pressure! So do check on these facts before you make a buying decision.