Cartridge Filter Question - When to replace?

[davisito45]

Hello,

I have a Pentair Clean and Clear Plus 420 with 4 Cartridges. I had the pool built in 2008 and have had the same cartridges since. I have cleaned them often and once with TFP. At what point should I replace them? There are no tears but they look discolored (yellowish). I recently cleaned and then two weeks later I noticed an Alarm message on my pool pump indicating the filter is blocked. I checked and no tears and no blockage so I reset the Alarm message.

Any suggestions?

FC 5.0
TA = 70
PH=7.6
CH=500
CYA=60
TEMP=60

 

[JasonLion]

You want to replace the cartridge(s) when the just cleaned the cartridge pressure starts to go up significantly from what it was when the cartridge(s) were new and an overnight detergent soak does not resolve the problem.

If handled carefully cartridges can last a very long time.

 

[davisito45]

Thank you for your response. I will keep an eye out for the increased pressure. Good to know it is normal for them to last a long time if handled carefully.