Hi,
I had a Pentair cartridge filter and used 420's for many years. It died and I got a slightly larger of a similar Pentair model, the salesman said it could take 420's or 520's.
I installed a new set of 4 520's yesterday and the initial pressure reading seemed higher. With the 420's a new clean filter would start at 12 PSI, with the 520 it seems to start at 16 PSI.
Am I right in thinking that since the total square area of the 520 is ~ 25% greater than the 420, the initial pressure reading would be 25% higher as well?
I had a Pentair cartridge filter and used 420's for many years. It died and I got a slightly larger of a similar Pentair model, the salesman said it could take 420's or 520's.
I installed a new set of 4 520's yesterday and the initial pressure reading seemed higher. With the 420's a new clean filter would start at 12 PSI, with the 520 it seems to start at 16 PSI.
Am I right in thinking that since the total square area of the 520 is ~ 25% greater than the 420, the initial pressure reading would be 25% higher as well?