- If you have the opportunity to purchase a system with a pump versus one without a pump, always choose the system with the pump. RO membranes produce more water as pressure increases. While your RO system may produce more than enough daily water without the pump, you will miss some important advantages without the pump. The reject stream of your RO membrane is what takes the removed contaminants to the drain. Systems with a pump allow a higher flow of water to run across the membrane. This generates more shearing force on the membrane which will do a better job of self-cleaning it and preventing fouling. It will also allow you to use mild chemicals on your system to condition the membrane and keep it running longer.
- RO membranes love soft water. Soft water keeps the membrane from fouling and the sodium (traditional salt softener) acts as a detergent and keeps silt and dirt from building up. You need not worry about adding salt into your diet because the RO membrane will remove 98 – 99% of it. If you have a smaller system (5- 100 gallons per day) I will soon be offering my own brand of a disposable water softener cartridge that you can replace every 3- 6 months.
- Upgrade your RO pre-filter, and if you don’t have one, have your supplier or local handyman install one. Here is one caveat, typically the filters sold at the local hardware store are rated as a nominal filter. Nominal filtration essentially means, more-or-less. Nominal filters tend to filter better over time as they get plugged up. The problem is when they are new they pass more particles than the rating size and over time this will prematurely plug up your RO filter. What you really want is what is called an absolute filter. Absolute filters provide the exact micron rating whether they are brand new or well-plugged up. Make sure the filter is 1 micron or less.
- RO membranes love warm water. If your RO system vendor is honest, his system output capacity in gallons-per-hour or per day, is based on a feed water temperature of 77 º F. For every degree F below that mark, your RO system will lose roughly 1.5% of production. So, here is another important caveat. If you purchase an RO that is rated at 200 gallons per day, and you actually need close to 200 gallons per day, your system will not produce that much if it is operating on cold water. If you live where it really gets cold, you could easily lose 60% of your systems rated capacity due to frigid water. Make sure to ask your vendor to rate your RO based on water temperature. The good news of course is that, if your RO runs on cold water now, and you need more, simply installing a blending valve, and raising the feed water temperature to 77 º F will get you more water and perhaps save you from buying a bigger system.