Pentek Big Blue water filter housings hold large-diameter filter cartridges in place and feed water through the housing cap. Big Blue housings are reliable and can withstand high flow rates. John Woodard, our Master Water Specialist, explains what makes Big Blue one of the most popular housings for water filtration. What is a Big Blue filter housing? Big Blue is a registered trademark by the Pentair company under the Pentek brand. The term "big blue" has become a Kleenex term in the water industry that refers to filter housings with a four and a half inch diameter filter. Big Blue water filters come in either 20-inch or 10-inch sizes. Who is Pentek? Pentek products relate to the water treatment industry. They also market products under OmniFilter, Everpure, Fleck, Shurflo, and WellMate. What makes Pentek filter housings unique? Pentek is well-known for its reliability. Pentair/ Pentek filter housings are popular choices in the water treatment industry because they've been around longer, they're reliable, and they're easy to use. How does a Big Blue water filter housing work? A Big Blue filter housing holds big filter cartridges. Other manufacturers don't describe their large diameter filter housings as Big Blue. Any term for large diameter housings refers to housings that operate the same way. Water enters one end and goes down through the housing. Depending on what type of filter cartridge you have, water might flow through the filter and then out, or it might go all the way to the bottom and flow up through the media in the drop-in cartridge. You can put a variety of filter cartridges inside a housing depending on what you're trying to filter out. What are Big Blue filter housings used for? These filter housings are used for point-of-entry (POE) filtration, typically residential. They can be used commercially with more flow rate than a standard-size filter housing. A lot of water can flow through a large-diameter filter housing, so it's used for a variety of applications. You can put a sediment filter, a carbon filter, or a specialty filter with ion-exchange resin or arsenic-reducing media in a Big Blue filter housing. What do Big Blue filter housings remove? The housing itself doesn't remove anything. It just directs water flow around whatever filter cartridge you put inside. The cartridge does the filtering, or separating the water from the contaminants. The filter housing itself doesn't do anything until you put something inside. And what type of cartridge you put inside determines what will be removed. What's the difference between Big Blue and other filter housings? Size. Big Blue filter housings work best with point-of-entry flow rates for a whole house. Smaller filters and filter housings are used at the point-of-use (POU). The small cartridges are designed to install under the sink to filter water to a dedicated faucet or with a combination of filters in a reverse osmosis system. Filter housings are designed differently to accommodate flow rate. If you're looking for a point-of-entry (POE) filter, you'll want something that can withstand high flow rate. And that's where the Big Blue housings come into play. How do you install a Big Blue filter housing? The Big Blue housing cap is threaded to match plumbing size. These caps are available in three-quarter, one-inch, inch and a quarter, an inch and a half thread sizes. When you're installing the filter and housing and you have an inch and a half plumbing, make sure the cap measure an inch and a half because you never want to reduce the size from your plumbing size. If you have a three-quarter-inch cap and an inch and a half housing, you can reduce the fitting down to three quarter with a bushing. If you're using your Big Blue housing commercially, just connect the water into it. The cap has an in and an out. The end is the feed side. The out is the filtered side. Make sure the in and out are lined up properly since the filter housing doesn't come on a mounted bracket. Then install your mounting bracket on to hand the filter housing on the wall. How often should you change a Big Blue filter housing? Every 10 years. Big Blue filter housings are dependable and last a long time. The manufacturer suggests that you replace it every 10 years. If the housing's been in place for 10 years, you probably should replace it. Every time you turn a faucet off while water is flowing through this filter housing, water hammering occurs. This means the inertia of the water flow stops with a force of energy. Many times water hammering causes the housing to move or flex. Eventually, the plastic could get tired of flexing and start to crack. Housings with clear sumps (body) don't flex like the blue ones or the white ones or the black ones. Clear filter housings use a different plastic blend that doesn't flex as well, so it cracks and fails much sooner than the polypropylene colored ones. We recommend you change a clear filter housing at least every five years so that you don't end up with a catastrophic failure where the housing cracks and water floods. Which Big Blue filter housing do I need? The Big Blue filter housing has a specific application in conjunction with the cartridge that we're going to use with it. The filter system that's right for you could include a combination of filter housings, like one with a sediment filter and one with a carbon filter for removing chlorine or taste and odors. The filter that's right for you really depends on your water quality. Do you need a water softener with a Big Blue housing? Not always. Many times, the Big Blue filter pretreats or protects the water softener. For example, if you're removing hardness from a well water supply that has a level of particulate in it, you'll hang a Big Blue filter before the water goes into the water softener so it can capture the stuff the water softener can't handle, such as oxidized iron. You can capture contaminants with a filter and a Big Blue housing to pretreat the water before a water softener.