Help with Hayward C3025 Pool Filter Cartridge Fitment Issue

[rajthepilot]

Hi everyone,
I’m having a bit of trouble with my pool filter and hoping someone here can help.

I have a Hayward C3025 filter, which uses 4 cartridges. Two years ago, I bought a new set of replacement cartridges and stored them in my pool shed over the winter (unheated, outside). This season, when I went to install them, one of the cartridges didn’t fit properly—it was extremely tight and I had to force the lid down to close it. Now I’m concerned I may have damaged the filter housing or something at the bottom.

Here are the details:

• Filter cartridges that I saw in the filter in 2023: UNICEL C-7477
• Replacement I purchased: SpiroPure SP-PS-6440, which my notes say are compatible with the Hayward C3025

However, I don’t remember this much resistance last year. Even the internal rack that holds the cartridges on top before putting on the lid was harder to install than usual.

I have two main questions:

1. Can filter cartridges shrink slightly from being stored over the winter (cold but dry conditions)?
2. How do I confirm which specific cartridge brand/model I should be using?
   • Are generics like SpiroPure generally reliable, or is it better to stick with name-brand cartridges like Pleatco or Hayward?

Thanks in advance for any insights or advice!