Why did my bleach leave?

[philanna]

Thanks again Janet. I'll watch it all day and add bleach as needed. I'll report back after this whole drain & shock business.
Anna

[philanna]

Goodmorning,
Ok so we drained and diluted our pool all night Fri. and Sat. morning.
I added some bleach Sat. even though we were still draining/diluting just to keep anything from blooming.
I had to go to pool store to get reagents, so I had them test water;
FCL=5.0+
TCL=5.0+
PH=7.6
ALK=90
CAL=160 (way off my #'s)
CYA=40 (way off my #'s)
TDS=1500
COPPER=0
Heres my #'s that I took about an hour later;(4:30p.m.)
FCL=9
TCL=9
PH=7.6
ALK=80
CAL=250
CYA=70
Here are my 9 pm #'s (i didn't add any more bleach yet, i wanted to see if it would hold at 9ppm.);
FCL=6
TCL=6
PH=7.6
ALK=80
CAL=210
CYA=60-70(this is a hard test for me, my eyes suck)
Ok so the chlorine did'nt hold so I added 3.7 gallons, then i retested chloine at 9:45, it was at least 20ppm, i think closer to 25, but thats with alot of dilution from shotglass method.
Now here are this morning test results;
FCL=20(AT LEAST)
TCL=20
PH=8
ALK=90
CAL=220
CYA=70(maybe 60, i suck at this test)

Now then from all I've read I should go by my results over the pool stores, so I say cya=70. My chlorine held all night. So now do I just need to add muratic acid to bring my Ph down? Should I shoot for 7.4?
And since my cl stayed all night am i done shocking? I have to leave today so I won't be able to test or add anything between 11am and 7 pm.
Thanks in advance for your help
Anna

[waterbear]

Your numbers have been relatively consistant. I would trust them over the pool store. I work in one and have seen very bad test results done in pool stores! You pH is fine at 7.6 but you really can't test pH accurately until your chlorine levels drop below about 10 ppm! If you chlorine held overnight I would let the levels drop and then retest. BYW, if you look on the lid of your taylor kit on the bottom of the chlorine test section it it will tell you how to dilute for testintg high chlorine levels....there are dilution markings right on the comparator for 1:1 and 1:4 dilutions. You don't need the shotglass!

[philanna]

Thanks for the quick responce. I'm glad I didn't just add acid without asking, this forum rocks!!! Wow, I can't believe I didn't read that on my Taylor box lid, I thought I've read everything like a hundred times . I'll test agian tonight, and I'm sure I'll be posting my numbers to make sure I'm OK.
Anna

[philanna]

Oh ya, should I leave my filter running untill my chloine level drops? Or should I let it run its normal cycle (8hrs per day) even though my CL is 20?

[chem geek]

It is possible that having your pump run 24/7 until the chlorine level drops might help make the chlorine level drop a little faster due to better mixing (bringing higher chlorine levels closer to the surface where it can get broken down by sunlight more readily), but this might be a minor effect. So the real answer is, "I don't know", but having your pump on might help and it certainly won't hurt (except for a somewhat higher electric bill). Once your chlorine is down closer to normal levels, you can return your pump to normal hours.

The main way to bring your chlorine level down is to keep the pool exposed to sunlight as that will break down the chlorine faster than most anything else.

Richard