Bad to keep spare pool filters?

[beachfrontpool]

We keep a spare pair of filters and swap them out regularly, cleaning them and letting them dry out. The man at the pool store just advised me that this is a bad idea, as letting them dry out will cause the fibers to "lock up" and stop absorbing. Is this true?

[SunnyOptimism]

I have a Pentair Quad-DE filter which is basically a quad style cartridge filter that is designed to use DE. The filter unit can be run without DE (not recommended by Pentair) and then it acts like a cartridge filter. I typically tear down the filter once per season, wash out all the old DE and fully rinse the cartridges.

The reason why I mention all this is because the manual specifically mentions the case where the cartridges can get "limed up" (pool industry term). Essentially that means that calcium (and, to a lesser extent, magnesium) can scale out into the cartridge filter fiber material as insoluble carbonates. "Limed up" cartridge media looks crusty white/grey and feels crunchy when you manipulate the pleats with your fingers. The fix for a limed up cartridge is to do an acid soak in 1:5 muriatic acid/water (as per the Pentair manual, other filter manufacturers might have different recommendations).

So, the pool store guy is not way off but I don't think his prediction is quite right. If you do store extra cartridges and rotate them as you say, then you should just add an acid soak (if the cartridge can handle it) if the filter becomes "limed up".

[kelemvor]

Re-using filter cartridges is very dangerous to the pool stores' revenue stream! Don't do it, they NEED the money!

All jokes aside, lots of folks do exactly what you're doing. As SunnyOptimism said, acid wash as needed (make sure to degrease with dishsoap before an acid wash). Replace the filters when they get holes in them - usually long after the bands start to break off.

Pooldoc wrote up detailed instructions on cleaning and maintaining cartridge filters here:
http://www.poolforum.com/pf2/showthr...ut-Damaging-It!

[Pool Clown]

As long as you clean the filters before they are allowed to dry out, they should be fine.

[FormerBromineUser]

Pooldoc wrote up detailed instructions on cleaning and maintaining cartridge filters here:
http://www.poolforum.com/pf2/showthr...ut-Damaging-It!

The expert! Love the internal link!