where to add bleach?

[medvampire]

kjmelak
The greaest concern with pouring through a skimmer is if you have a puck feeder and have ever had pucks in the feeder. The problem come from the diffrent types of chloring mixing. I understand bad things can happen (like puck feeder go boom) by mixing diffrent types of chlorine.
Some members here great luck pouring in to the skimmer but being I do have a puck feeder and use it now and then I pour in front of the returns. As watermom mentioned you migh want to get Bleachcalc you can download it here.
Steve

[chem geek]

Even if it were only 60 gpm that's one gallon per second.

This is true except that you need to divide this rate by the number of intakes which is typically 3 -- two floor drains and one skimmer. So that is still a speedy 1 gallon every 3 seconds so you are right that you wouldn't pour it that fast.

You probably couldn't pour it in much faster than one gallon over 10 seconds and more likely over 15 seconds so that's 1/5th of a 50/50 mixture which is certainly more diluted and reduces the pH increase by about log10(1/5) = 0.7

When this is in the water stream, it is at this elevated pH and hits your filter wherever it is entering your filter. I agree that by the time it spreads around your filter, it's not a problem, but it's that first area of exposure that was of concern. Remember, I was only asking the question, not at all sure that it was a problem.

Anyway, given how most people probably pour more slowly, putting it into the skimmer is probably OK, at least for bleach. For the liquid chlorine at pH 13, that's a little riskier.

Richard

[KirstenHW]

Sadly I cannot comment at all on the chemistry equations - I worked for my B in eleventh grade Regents chem all those years ago. However, I am now nervous as I have on occasion poured the bleach around the entire perimeter of the pool with the pump running - especially at opening. I have an 24 gal 18x42 vinyl ig with a 3 ft shallow end. Of late I have been adding the bleach to one of the 2 skimmers (one closest to non-cartridge DE filter). I add 1.46 gallon jug over the course of about 1-2 minutes time.

I won't do the perimeter thing any more - but was that really bad to have done?

[sailork]

KirstenHW, bleach mixes very quickly with the water when you add it. I think a lot of people add bleach the way you are describing it and it isn't a problem. It's probably better to add it in front of a return, but I'd doubt you've hurt anything by just dumping it in.

chem geek, I appreciate all the math and stoichiometry you present in your posts. It has really helped demystify the chemical processes going on in my pool. (And a big shout out to Evan for the same thing.) I suspect this thread may be getting near the China Shop Event Horizon given Ben's desire to keep from scaring people with too much information in the general forum.

[kjmelak]

Wow! Thanks for all of the replies. I was basically concerned with bleaching my liner (I have an AG Pool) if I poured it in front of the returns. Sounds like the general consensus is that I will be fine either way. Thanks again!

[CarlD]

Wow! Thanks for all of the replies. I was basically concerned with bleaching my liner (I have an AG Pool) if I poured it in front of the returns. Sounds like the general consensus is that I will be fine either way. Thanks again!

Yup, that's right.