Am I using too much bleach?

[RockingM]

25,000 gal pool
Free chlorine drops by approx 2 each day
Combined chlorine is almost nonexistant
Just switched pool from tabs to bleach last week
ph at 7.8 consistently
alkalinity at 130
calcium at 210
CA at 40

I'm using 2-3 gals of bleach each evening. It pushes my chlorine up to 5 or 6. It stays steady overnight. But by day's end it's back down around 1-2.

Does it seem right that I'm using 2-3 gallons of 6.00% bleach per day?

 

[Richard320]

Editted

2 gallons of 6% bleach is only 2.5 5 parts per million, which is reasonable. Taking CYA up to 50 might save a cup or two every day. high.

Recheck that CYA and if it is indeed 40, something besides sunlight is eating it. An overnight loss test will confirm it. If it fails the test, you need the Shock Level And Maintain process. If the water's clear, it could still be done before the Fourth of July party.

 

[Smeade]

Rocking M, I'm a newbie here, so wait for my suggestion to be seconded by one of the Pros. I'm responding because you've been waiting a while and I'm sure you'd like some kind of an answer.

So, what is the percentage of the bleach you're using and where did you get it? Some of the dollar store bleaches aren't very high in actual chlorine, so you may not be getting much bang for your buck. Also, the bleach could be old, and it loses its potency over time.

Are you using pool math? Two gallons of 8.25% bleach would raise my FC by 7 (I have a 24K gallon pool). I lose about 3ppm FC every day (so your 2ppm isn't bad).


Also, how did you test your water for the 40 CYA?

Somewhere to start! Good luck! Someone with more knowledge/experience will be along soon to help you further.

- - - Updated - - -

Duh. If I would read your whole post and not be so eager to "help", I'd see you we're using 6% bleach. I'll go back to lurking now.

 

[mrcarcrazy]

Do you test after you add to make sure you're reaching the point you think you are? Reason I ask is you may very well be using old bleach that's more like 3.5%

When you say "FC drops by 2 every day" you mean 2ppm? if so 2ppm isn't much.(But your later statement contradicts that..) I found that 6% bleach is cheaper/gal but the irritation of using more than 8.25% was worth me using 8.25% (Until I can get my 12.5%). But if 2ppm is the case, then your bleach is absolutely not 6%....as per Pool Math It should take 104oz to raise your FC 2ppm. Similarly, 242oz (2x121oz jugs) would raise your FC by 4.7. I'm assuming that your "gallon jugs" are really 121oz. (which could be wrong, that's just the more common size where I live)


What test kit are you using?
No Chlorine loss overnight?

 

[RockingM]

Looks like I need to do the OCLT test for a couple of days... Thanks for the feedback!

 

[freqz]

If your FC is 5 or 6 in the morning and 1-2 at night then you're dropping 3-5 ppm FC per day, right? Or am I confused? (it's been known to happen)

Either your CYA level is less than 40 and a bright Texas sun happily eats your FC every day

OR

Something has set up shop and is happily eating your FC

OR

6% bleach is more like 3% in this case...

How's the water? Sparkly and clear?

 

[RockingM]

Bumped up chlorine significantly last night (to 19 - I think my pool may be smaller than my measurements show). Performed the OCLT last night. Passed the test! Chlorine was at 18.5 this morning.

VERY curious to see if chlorine "only" drops by 3 today...

 

[Smykowski]

Chlorine loss is a %, not an absolute value. Since you're starting the day significantly higher, your loss might be higher.

What test kit are you using?

 

[RockingM]

This test kit: http://www.amazon.com/gp/product/B004BGF7TI/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1

TAYLOR TECHNOLOGIES INC K-2006 TEST KIT COMP CHLORINE FAS-DPD

 

[Smykowski]

Raise your CYA to 50 and see if that helps.