System Selection in Action: Choosing the Right Multi-Media Filtration Unit

Everfilt® M-Series Multi-Media Filtration System

When it comes to water treatment projects, equipment selection is rarely straightforward. A recent project provided a great example of how engineering questions + practical considerations shape the final system choice.

We were working through the design of an Everfilt® M36-48-3A Multi-Media Filtration System, and here are a few of the key decision points:

1️⃣ Flow Rates – Filtering vs. Backwash

The minimum flow (174 GPM) is governed by the backwash requirement; you need enough velocity to lift and rinse the media bed. During normal operation, the unit can run at much lower incoming flows (30–75 GPM).

Solution: Adding isolation valves to top and bottom of a tank gives the operator flexibility to bring tanks online/offline as flows vary. ( remember specific diameter tanks and media beds require specific gpm and pressure to ensure proper backwash sequence )

2️⃣ Skid Dimensions & Site Fit

Standard 3-vessel skid: 113.5” L x 41.6” W x 111” H.

Always confirm door clearances ( in this case, 10’ x 10’ ) and ask about 1- or 2-vessel alternatives if access is a concern.

3️⃣ Pump Sizing

A proposed 1 HP end suction pump ( 90 GPM @ 18 ft TDH ) wouldn’t cut it, the pressure losses through filters + dual GAC vessels + storage tank would overwhelm it. For this application, a 5-7 HP pump was recommended to maintain performance.

4️⃣ Application-Specific Needs

The project involved remediation treatment with coagulation/flocculation upstream. Fine 20-micron filtration was required to capture smaller metal particles. For less critical uses ( e.g., dust suppression ), a shallower media bed would have been sufficient, but here, a deeper 48” bed was the right call.

5️⃣ Lead Time & Finish

Standard lead time: 5 weeks.

Standard finish: Blue, with custom colors available

( though may extend lead times ).

✳️ Takeaway:

System selection is about more than picking a model number; it’s about understanding the process, the site, and the operational requirements. By weighing flow rates, skid fit, pump capacity, and application-specific needs, the team was able to select the right configuration with confidence.