High chlorine consumption

[David ATX]

Will non circulating water eat more chlorine in sunlight then water that is moving? I live in Austin TX, and since the weather started warming up to upper 80s-low 90s, my pool has been eating 4-4.5 ppm in chlorine daily. That’s almost 2ppm more than the peak of last summer.

My CC is 0.0, my OCLT is fine, my CYA is 50, and my water is crystal clear. I’m at a loss as to why my pool is going through so much chlorine.

I run my pump from noon to 8 pm, so is it burning off in the early day hours when the pump isn’t running?

 

[woodyp]

Are you taking your water samples from about elbow deep? Circulation helps mostly replenish FC burned off on the top foot of water or so keeping it mixed.

 

[David ATX]

Are you taking your water samples from about elbow deep? Circulation helps mostly replenish FC burned off on the top foot of water or so keeping it mixed.

Yes, the water sample is always inserted upside down, elbow deep, then filled and removed.

I thought that perhaps the chlorine batch I have might have been old, but I retested about an hour after my dose this morning and it was exactly where I expected it to be. I should have mentioned that I also run the pump from 7-9 am specifically for my daily chlorine dose in the morning.

 

[Oly]

Odd. Good that you checked our FC after adding the chlorine that eliminates a weak batch. You are confident that your CYA is actually 50?
How many people are using the pool and for how long? Any kids in the pool? Any pets swimming? Are you getting high winds? What is your water temp? Compare you loss overnight verses the day to isolate the period of high demand, but if you are passing the OCLT then it must be during the day.

I'm thinking if the loss is during the day then it is either bather load, debris or loss from sunlight.

 

[David ATX]

Odd. Good that you checked our FC after adding the chlorine that eliminates a weak batch. You are confident that your CYA is actually 50?
How many people are using the pool and for how long? Any kids in the pool? Any pets swimming? Are you getting high winds? What is your water temp? Compare you loss overnight verses the day to isolate the period of high demand, but if you are passing the OCLT then it must be during the day.

I'm thinking if the loss is during the day then it is either bather load, debris or loss from sunlight.

We did have a massive rainstorm a week ago and I had to drain about 4” of water from the pool to prevent it from overflowing, but I can’t imagine that dropped my CYA significantly. No heavy swim load, but it has been kind of windy lately. But nothing crazy, just 10-15 mph gusts from time to time.

 

[Kiss4aFrog]

I know you said no heavy swim load, any chance more time in the spa than usual ?

 

[David ATX]

I know you said no heavy swim load, any chance more time in the spa than usual ?

Nope. Just the wife and I a week ago, but nothing out of the ordinary. Ultimately I was wondering if still water burns more chlorine than moving water.

 

[kellyfair]

Is the CYA test result from today?

 

[David ATX]

Is the CYA test result from today?

No, but it’s recent (about a month or so ago). And other than the 4” I drained, there’s no other reason my CYA would have dropped.

 

[kellyfair]

Just for kicks, can you check your CYA again?