Pool Filter unions are slightly cheaper than their pool pump union counterparts due to the simple reason that pool filter unions are not exposed to the heat and vibration that come from pool pumps. 

Every once in a while, your pool sand filter’s multiport valve may need cleaning or maintenance and to make the job easier, you can have pool filter unions installed. This is so that you can take the entire multiport, sit down in a nice comfortable area (with a desk or work table!) and do the maintenance work properly. Without pool filter unions, you will have to either remove the plumbing (which takes time, money, and a lot of effort) to be able to bring the multiport to a table, or you will have to work there awkwardly with the multiport hard plumbed into your pipes. 

For more information on troubleshooting and maintenance, you can check out our multiport repair guide here. 

Pool Filter unions also need no special maintenance aside from an annual checking of the O-ring. If the O-ring is fine then just add a bit of Aussie Gold Lube-It or any silicone based lubricant and you’re good to go. 

If you find that your unions are leaking then the cause is more often a faulty O-ring, which can be purchased for just a couple of dollars at your local hardware or handyman store.