Problems with Your Commercial Water Treatment System? Your Filter Might not be Properly Sized.

Your commercial water filter is a critical part of your water treatment system. Like a coffee filter, it removes solid particles from your water. But it also filters out the things you can’t see—including tiny iron and manganese particles. If you’re having problems with your water treatment system, your filter may not have been sized properly.

“There is a tendency for many water treatment companies to size commercial filters based on the water flow needed to treat, but that’s not enough,” says Steve Guercia, commercial water treatment manager with Secondwind Water Systems. Guercia points out that there are many factors that go into properly sizing a commercial water filter.

How a Commercial Water Filter Works

With some water treatment systems, a cartridge filter is used to remove the contaminants mentioned above. The tiny particles are pulled away from the water and collected in a filter, which is periodically replaced. This is adequate for treating small volumes of water. But when it comes to treating thousands of gallons of water a day, a commercial backwashing filter is needed.

Backwashing water filters are large, tank-style filters.  They clean and renew themselves on a set schedule based on time, gallons, or water pressure. Through the water backwashing process:

  • water flow is reversed so it enters from the bottom of the filter bed (medium)
  • the filter bed is lifted and rinsed
  • water exits through the top of the filter tank

“A backwashing filter is a great way to remove iron and sand from water. If you use the right medium (or combination of media), you can also remove chlorine or other contaminants,” Guercia explains.

Properly Sizing Your Commercial Water Filter

Flow Rate

Like all treatment systems, filters must be sized to treat your required water flow rate. But unlike most other treatment systems, filters require a lot of water to backwash. For example, if your filter is sized to treat 10 gpm, it might need 20 gpm to clean itself. If you install a filter to treat 10 gpm (what your well is able to produce), how will you  backwash it if you need 20 gpm? This question can be best addressed by a certified water treatment specialist at Secondwind Water Systems.


The type of medium you use in your commercial water filter is determined by the kind(s) of contaminant(s) you want to remove from your water.

Common types of media include:

  • manganese dioxide
  • greensand
  • garnet
  • anthracite
  • zeolite
  • granular carbon

Leading brands of media include:

  • Macrolite
  • Filter Ag
  • BIRM
  • MTM

Flow Rate and Media

Depending on the media your commercial filter uses, your backwash rate can range from 60% of the treated flow to twice the treated flow.

Because the Secondwind team understands the water issues in your region, we can determine the best medium or combination of media for your system. From there, we can custom-design a commercial water filter system that optimizes your flow rate, providing the water capacity you need. For example, to meet your needed backwash rate, you could either install multiple smaller systems in parallel, or use stored water. There are many other options for doing this that are beyond the scope of this blog. “Any filtration system you install must carefully balance and integrate all controls. If this isn’t done correctly, your filter will fail,” says Guercia.

Commercial Water Filter Sizing, Installation, and Repair

Whether you need help improving the performance of your existing commercial water filter system, or want to purchase a new one, the Secondwind team is here to help. We’re happy to look at your system to help you determine why it’s not working as well as it should. Frequently, we can save a failing commercial water filter system with a few adjustments or modifications. Contact us today for your free consultation.