Ever see two water filters from the same company that had part numbers so similar that you simply couldn’t tell the two products apart? If so, then you, “Gary” and a whole host of other people — including ourselves — have something in common!

Today we will attempt to help Gary differentiate between the Pentek P5-20 and the Pentek PD-5-20 water filter elements.

Can you please tell me the difference between using Pentek PD-5-20 and P5-20 filters? I have a big blue cannister for sediment removal but also have a whole house prefilter that h as a P5-20 filter in it. Can these be used interchangeably so I don’t have to buy 2 different filters? Gary

We first must say this: The info we will give next comes from web sites whose content we cannot verify… but if you visit the Filters Fast web site, since we know Filters Fast sells both of the products in question, and ask them a question using their live chat ‘thingie’, or send them an email, we believe you could verify the info relatively quickly.

And so…

Based upon what we read, Gary, you ought to have no problem interchanging the two filters BUT pay close attention to the flow rate, as they vary greatly.

  • P5-20 has a flow rate of 10 GPM @ 0.6 psi.
  • PD-5-20 has a flow rate of 5 GPM @ < 2 psi.

We also noticed that the diameters differed by about an eighth of an inch (.125″) and that the Pentek PD-5-20 has a higher max temperature rating of 175 degrees Fahrenheit (80 degrees Celsius).

The diameter ought not matter if you have a standard sized 20″ pre-filter housing.

Important Note: Do not attempt to use “Big Blue” filters, as they feature a much wider, non-compatible diameter of around 4 1/2 inches!

Filters Fast: Pentek P5-20 Sediment Filter
Pentek P5-20 Sediment Filter
Faster Flow, Lower Temp Rating

Filters Fast: Pentek PD-5-20 Sediment Filter
Pentek PD-5-20 Sediment Filter
Slower Flow, Higher Temp Rating