Downsides of high FC

[jefeyessica]

What, if any, are the downsides of keeping a high FC?

For example, with my CYA, the pool calculator suggest a FC range between 4.0-8.0. Would there be any disadvantages to bringing it up to 10 or 11 at night? That way, when my pool uses 3ppm, it will go down to 7 or 8 by the following night. I like the idea of doing this, because it protects my FC from going too low by nighttime.

 

[dmanb2b]

shouldn't be a problem...I would split the difference...target 9ppm and you'll end up at 6ppm in the evening...you'll still be 2ppm above your minimum

 

[JasonLion]

The only significant down side is that you will use more chlorine that way.

 

[jefeyessica]

How do you use more chlorine that way? Doesn't it still burn off at the same rate?

 

[JasonLion]

The amount of chlorine used up by sunlight is a percentage of your starting level. A higher starting level means more chlorine used by sunlight. Chlorine used keeping the pool sanitary will be the same either way.

 

[jefeyessica]

Really? :? Interesting. I wonder why it's a percentage, instead of a set number... Any chemical reasons for that?

 

[dmanb2b]

Let me see if I can try to explain (hope my thinking is right here) sunlight burns the chlorine at a certain rate...the more chlorine you have in the pool as a percentage of your pool water the more chlorine you will burn.

 

[JasonLion]

To add to what dmanb2b said, all of the chlorine is exposed to sunlight. If there is more chlorine then more chlorine is exposed to sunlight. Chlorine breaks down at some rate when exposed to sunlight (the rate depends on the CYA level and the intensity of the sunlight). All of the chlorine will be breaking down at the same rate, so more chlorine means more of it breaks down.

 

[jefeyessica]

thanks for the clarification!