I just dont 'get' adding CYA.

[setsailsoon]

I think the negativity here comes from "experts" at pool stores pushing trichlor pucks (and other chemicals) without the required knowledge of water balance chemistry, especially about the reduced disinfection properties as CYA/FC ratio increases. Once you learn about water balance it becomes easy to use pucks appropriately. For example, many of the TFP users do add pucks in floater for vacation. It works well so long as you make sure you know where you will start and end with respect to CYA ratio. But with the longer season as others pointed out pucks are not a solution unless the owner plans to drain a LOT of water throughout the year. In my experience pool stores never point this out.

I hope this helps.

Chris

 

[tcat]

Could be we got tons of rain this winter, probably drained of 6" of water 3 or 4 times. That with evaporation (Texas heat and wind), I probably exchanged 50% of my water in 4 months. So nothing besides water replacement will drop cya?

 

[mknauss]

Evaporation loss does not reduce CYA.

CYA does degrade over time. That degradation is accelerated at elevated pool water temperatures (90F+)

 

[setsailsoon]

Could be we got tons of rain this winter, probably drained of 6" of water 3 or 4 times. That with evaporation (Texas heat and wind), I probably exchanged 50% of my water in 4 months. So nothing besides water replacement will drop cya?

There are some naturally occurring soil bacteria that can metabolize CYA but they can't exist in a well-balanced pool. I suspect they may have a role in some pools that are closed for winter and have reported 0 CYA when they open. Even at temps averaging 85+ deg my only significant CYA loss seems to be from draining excess rain during wet season.

Chris

 

[cfherrman]

When it rain, or before, you can run some water to waste and then it rains like 3". You just replaced some water and lowered your cya, ch, salt, and ta a little bit. If you have enough rain and do this when it rains it opens up triclor and Cal hypo.

A lot of old school pool people backwash their sand filter every week, this reduces their sand filter effectiveness but they are replacing water every time, helps a little on triclor usage but hurts the filter effectiveness more.