Generally, the water quality in the Boston area is good, but drinking water can be contaminated at any point in the water purification and delivery processes. Because many homeowners are concerned about contaminants such as lead, mercury, chlorine, petrochemicals, fertilizers, and prescription drugs, they are turning to a type of water filtration system known as reverse osmosis (RO). The professionals at Boston Standard Plumbing can recommend and install water filtration systems, including RO and whole-house filters.

A reverse osmosis filter isn’t like the filter you may install on your kitchen tap. Instead, a reverse osmosis filter is normally installed under the sink and relies on high pressure (35psi or greater) to push unfiltered water through a filter membrane. The membrane does not permit most minute contaminants to pass. The filtered water is stored in a multi-gallon tank and is used for cooking and drinking.

Reverse osmosis doesn’t filter out everything; most nitrates are removed, larger particulates and minerals generally don’t pass through the filter. Bacteria and other organic contaminants may pass through the membrane. RO filters are usually outfitted with companion carbon pre-filtration systems that remove sediments, chlorine and other odor-producing contaminants from the water.

Before you decide on the type of water filter you want, you should know (or learn) a little bit about your water. If your primary problem is odor or foul taste, a simple carbon filter may solve your water quality issues without the added expense of RO installation and maintenance. If your water is contaminated with microbial organisms, a RO filter won’t “purify” the water in this regard, but an ultra-violet (UV) filter might. RO filters will reduce but not eliminate nitrates in the water; only distilling will eliminate nitrates. Extremely hard water can be softened with the use of a water softener; softened water can then be filtered.

Generally, homes that are attached to a municipal water supply receive high-quality drinking water in most circumstances. If something is causing local contamination of a home’s water supply, the municipal water authority should be consulted before any remedial action is taken. The biggest disadvantage of a RO filtration system is the amount of water that is sent back down the drain following the filtration process. RO filters produce anywhere between 5-10 gallons of “waste” water for every one purified gallon of drinking water. Some filters are slightly more or slightly less efficient.

In areas where the water is exceptionally hard (>10 grains/gallon), RO filter membranes will clog and fail much sooner than the manufacturer’s estimate. In many cases, using an RO filter with extremely hard water will void the manufacturer’s warranty.

It’s also important to ensure that your RO system is properly plumbed. In plumbing, copper piping is usually the “gold standard.” With RO systems, that’s not the case! The filtered water will have a higher concentration of CO2 because it will remove the natural salts in the feed water, but will pass all of the CO2 in the feed water. This combination of CO2 and reduced salts will damage copper piping, so no copper should be used on the side of the system that handles the purified water. This means you’ll need to pay attention to the plumbing at the fixture.

If the water pressure in your home is not sufficient to make the RO system work, a booster can create added pressure for better filter performance. You may also want to add a leak detector. Leak detectors can also be useful on other appliances that require a water supply like icemakers, humidifiers, coffeemakers, dishwashers and laundry appliances.

RO systems are used primarily for cooking and drinking applications. They’re not intended to filter the water supply for an entire home, nor would you want that. There are “whole house” filters that will remove chlorine and minerals from the water, but generally, these whole house filters don’t operate like reverse osmosis filters do.

If you are interested in having a RO water filtration system installed, or would like a consultation on RO filters or whole house water filtration systems, please contact Boston Standard Plumbing & Heating. We can help you determine what kind of water filtration system will benefit your home and family based on your water supply. We can also ensure that your water filtration system is installed properly and is free of leaks.

DIY Blog, DIY Plumbing

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