Chlorine level dropping quick with Cal Hypo

[ejs873]

I recently switched from liquid chlorine to HTC Cal Hypo shock since I am not around as much this summer to add liquid twice a day. Initially I had good results, with 1lb lasting almost a week. Recently I have been using a pound every other day. Is this normal for a shock to burn off that quick? All of the reading I have done makes it seem like it should last closer to a week. It has been super hot here lately so that might have something to do with it. I haven't noticed any algae and the water is crystal clear, but after 48 hours the chlorine level is under 1ppm. If its burning off that quickly, I might as well switch back to liquid.

Readings about 2 hours after adding 1lb of shock today:
PH 7.8
FC 3.2
Alk 180
CYA 55

 

[mknauss]

Regardless how you add it, chlorine must be added daily during the summer.

 

[Donldson]

Once it is in the pool chlorine is chlorine, no reason to think cal-hypo would act differently than liquid chlorine. 1 pound of 56% cal-hypo (the most common strength of HTH) will add 6 ppm FC. You should be expecting 2-4 ppm of chlorine this time of year easily, so 6 ppm burning off after 2 days seems quite reasonable.

No reason not to switch back to liquid chlorine, but do make sure you are following the FC/CYA Levels. You really only need to add once a day, maybe even every other day as long as you're adding enough that you never drop below the minimum.

 

[ejs873]

Once it is in the pool chlorine is chlorine, no reason to think cal-hypo would act differently than liquid chlorine. 1 pound of 56% cal-hypo (the most common strength of HTH) will add 6 ppm FC. You should be expecting 2-4 ppm of chlorine this time of year easily, so 6 ppm burning off after 2 days seems quite reasonable.

No reason not to switch back to liquid chlorine, but do make sure you are following the FC/CYA Levels. You really only need to add once a day, maybe even every other day as long as you're adding enough that you never drop below the minimum.

Thanks. the HTC recently went way up in price here, so If I am adding that daily it might be worth it to use the liquid. So the term "shock" is meaningless? I could add a pound a day and it wouldn't hurt anything?

 

[pjt]

What's your CH level?

I'd recommend getting a SWCG to solve your chlorinating needs.

 

[Newdude]

Readings about 2 hours after adding 1lb of shock today:

FC 3.2

1 lb of 48% cal-hypo makes 5.2 FC in 11k gallons. The stronger ones are more FC. If you lost 2+ FC in 2 hours, something is possibly brewing.

I would Overnight Chlorine Loss Test and remove the sun from the equation.

 

[ejs873]

1 lb of 48% cal-hypo makes 5.2 FC in 11k gallons. The stronger ones are more FC. If you lost 2+ FC in 2 hours, something is possibly brewing.

I would Overnight Chlorine Loss Test and remove the sun from the equation.

yeah.. ill try that. seemed extra fast today.

 

[mknauss]

So the term "shock" is meaningless?