Pentair DGD Series Dual Gradient Jumbo Filter - 25 to 1 Micron, 10" or 20" NZ

A single cartridge that works as two — coarse outer layer catches heavy sediment, fine inner core catches the rest.

The Pentair DGD Series Dual Gradient filter is a depth-graded sediment cartridge made from 100% pure polypropylene. The outer layer filters at 25 micron, removing sand, silt, and visible particles. The inner core filters at 1 micron, capturing fine particles before water reaches downstream equipment. Because the outer layer protects the inner core from loading too quickly, the cartridge holds significantly more dirt than a standard single-density filter before restriction builds.

Available in 10" (DGD-2501) and 20" (DGD-2501-20) for standard Jumbo (Big Blue) 4.5" housings. Select your size using the dropdown above.

How the dual gradient design works

A standard single-density cartridge filters at one micron rating throughout. As sediment accumulates, the whole cartridge loads evenly and restriction builds quickly.

The DGD Series uses a gradient density — the outer polypropylene is looser at 25 micron, capturing the bulk of the sediment load. The inner core is tighter at 1 micron, handling fine particles. The outer layer does the heavy lifting and slows down how quickly the inner core loads, which extends the overall service life of the cartridge.

This makes the DGD particularly well suited as a pre-filter before a UV system, where fine filtration is required but frequent cartridge changes are inconvenient.

Key specs at a glance

• Outer layer: 25 micron | Inner core: 1 micron
• Material: 100% pure polypropylene
• Diameter: 4.5" (Jumbo / Big Blue)
• Lengths: 10" (DGD-2501) or 20" (DGD-2501-20)
• High dirt-holding capacity — dual gradient construction
• Fits standard Jumbo (Big Blue) 10" and 20" housings

Which size do I need?

• 10" (DGD-2501) — fits standard Jumbo (Big Blue) 10" housings. Suited to most whole-house setups and UV pre-filtration.
• 20" (DGD-2501-20) — fits standard Jumbo (Big Blue) 20" housings. Higher dirt capacity and longer service life. Suited to larger homes, farms, and high-demand installations.

Match the length to your existing housing. Both are 4.5" diameter — standard Jumbo / Big Blue sizing.

Full specifications

What's in the box

• 1 x Pentair DGD Series dual gradient sediment filter (size as selected)

Frequently asked questions

What does "dual gradient" mean?

It means the cartridge has two filtration densities in one — a 25 micron outer layer and a 1 micron inner core. The outer layer captures coarse sediment first, which protects the inner core from loading too quickly. The result is a longer service life compared to a single-density 1 micron cartridge of the same size.

Is this a good pre-filter for a UV system?

Yes. UV systems require fine filtration upstream — particles in the water reduce UV penetration and treatment effectiveness. The DGD's 1 micron inner core meets that requirement, while the 25 micron outer layer extends the time between cartridge changes by absorbing the bulk sediment load before it reaches the fine inner core.

Will it fit my Big Blue housing?

Yes, if your housing is a standard Jumbo (Big Blue) 10" or 20" size. Both models are 4.5" in diameter — the Jumbo / Big Blue standard. Check your housing length before ordering — the 10" and 20" models are not interchangeable.

How often do I need to replace it?

Replacement interval depends on your water quality and sediment load. The dual gradient construction extends service life compared to a standard single-density 1 micron cartridge. Replace when flow drops noticeably or the cartridge is visibly saturated.

Can I use this on bore water?

Yes. The 25 micron outer layer is well suited to the sediment loads typical of bore water. If your bore water is particularly high in sediment or has unusual chemistry, get in touch and we'll help you choose the right filtration setup.