Why are cartidge filters and high CYA is a No-No?

[mikemass]

I was reading through the Pool School Definitions Page.
Pool School - Definitions and Abbreviations

I came across this comment under the definition of Dichlor:

Causes CYA to rise with continued use so it is not a good choice for those with cartridge filters

I don't use dichlor, nor do I care about it. But what I do care about is why does that comment suggest that if you have a cartridge filter, you should not have a high CYA? Or am I reading that wrong?

Please no comments about the fact that Dichlor contains Stabilizer and that is reason. I get that. My question has nothing to do with Dichlor, it just happens to be the place I found this comment about the CYA/Cartridge relationship.

 

[RobbieH]

That's odd. It probably needs to be re-written.

 

[JoyfulNoise]

You did not post the entire quote -

Causes CYA to rise with continued use so it is not a good choice for those with cartridge filters or in climates that do not winterize pools and have an extended swim season.

The point is, if you don't have a lot of freshwater exchange with dichlor use, the CYA will build up. Cartridge filters are not backwashed so you lose that option to dump water periodically.

 

[cowboycasey]

That statement is because 90% of cartridge filter setup's do not have a backwash or a 3 way valve to pump water out of the pool, and as you know once CYA gets high the only way to drop it is by dropping the level of water in your pool..

Some have started using 3 way valves like I did to make it easy to drop water level

 

[RobbieH]

You did not post the entire quote -



The point is, if you don't have a lot of freshwater exchange with dichlor use, the CYA will build up. Cartridge filters are not backwashed so you lose that option to dump water periodically.

Ah, there you go. I didn't even think of that. You can tell I'm a die-hard sand filter fan.

 

[mikemass]

The thing I love here is the speed in which you guys respond to a new post. TYVM!

Although (like mentioned) I do not have a Multi-port the way Sand and DE filters do, what I did install was a 3 way valve after the pump providing a "Blow-out" for when I need to dump water or choose to vacuum to "waste".

When I first read the comment I was thinking it was suggesting that Cartridge filters "trap" the stabilizer, thereby not allowing any into the pool. This clearly is NOT the case correct?

 

[jblizzle]

Correct. It is just because cartridge filters do not regularly dump water for cleaning so the CYA builds up faster.

 

[Divin Dave]

Yup. Those of us with cartridge filters have learned, that eventually a 3 way valve between pump an filter could come in handy. I put one on mine.

The thing I love here is the speed in which you guys respond to a new post. TYVM!

Although (like mentioned) I do not have a Multi-port the way Sand and DE filters do, what I did install was a 3 way valve after the pump providing a "Blow-out" for when I need to dump water or choose to vacuum to "waste".

When I first read the comment I was thinking it was suggesting that Cartridge filters "trap" the stabilizer, thereby not allowing any into the pool. This clearly is NOT the case correct?