Too much chlorine

[kkpjm]

For the first time, i decided to open the pool this year myself, because the pool guys are now asking for $250 to open it even if I install the laddders, board and uncover the pool before they get there...that being said, the local supply house instructed me to shock first before I even brought them a sample...5 gallons of liquid chlorine in a 33000 gal inground vinyl pool. Did that, everything is up and running fine, pool is clear and sparkling in 1 day. Took a sample in and it measured at 10.0 free chlorine! The guy said to wait a few days...it's been 3 days and it measured at 10.0 again today. he said I just have to wait. Is there any way to lower chlorine level effectively? Kids are dying to swim this holiday weekend, I told them when I opened it last weekend that it would be ready.
I'm thinking the inital dose was too much...they guy first said to put 10 gallons in but then said to try the 5 gallns and see if it was enough...CYA levels tested at 45 ppm the day after opening, today tested at ZERO. I'm beginning to question this newfangled computerized testing contraption they installed.

 

[RobbieH]

That sounds to me like there's something wrong with your test kit. CYA can't really go from 45 to 0 in a few days without draining your pool.

If my CYA was 45 and FC was 10, I'd swim in it, but that's me.

 

[woodyp]

If you don't have one of the two great test kits recommended here in pool school (yet).......take a water sample to someone else in your area and at least crosscheck them. If your CYA is 45 or so............you're good to go. I promise you it's gonna drop! But anything below the shock value for that level of CYA at 16 or 18 ppm is safe.

 

[Bama Rambler]

5 gallons of 12% chlorine would have raised your FC by 20 ppm. I suspect that their test only goes to 10 ppm and that's what they're telling you it is.

Without knowing your CYA level I hesitate to recommend swimming but I would if it were my pool.

Without beating a dead horse you really need your own test kit. The TF-100 is the best. With that, you'll know what your FC and CYA are as well as the other levels.

 

[kkpjm]

Thanks for the quick notes...I plan on taking a sample to another shop and cross-check. The discrepancy in the two tests just doesn't make sense.

Hopefully a couple days of full sun and SWG turned off will take care of the CL. It's supposed to be 90 degrees and sunny until Monday! THEN...I gotta get my own test kit. No horses will be beaten/harmed in the opening of this pool LOL

 

[kkpjm]

Today I took a new sample to the old pool guy, who uses a real honest-to-goodness test kit (a Taylor)...and he came back with FC @ 4.8, CYA at 45, PH 7.6...can't understand why I decided to try the computerized way. The guy suggested testing the system by taking two samples to the computer guy, both taken at the same time and location, and go in with a buddy as if we both were getting independent tests. He practically guaranteed me that i would two different results. I'm not even gonna go there.

There's a Leslie's right down the road from work...tomorrow lunch break means my own test kit.

It's hot in SE Pennsylvania today...swimming tomorrow...kids will be doing the Bill Cosby "Dad is Great" song when they get home from school!

 

[RobbieH]

FYI, none of the Leslie's kits have the FAS/DPD Chlorine test, but you can add just that kit from tftestkits.net. Otherwise, just order the full TF-100 or K-2006 from the site. You'll have it in a couple of days in my experience.

 

[chem geek]

Actually, Leslie's has a Chlorine FAS-DPD Service Test Kit, but hardly any stores have it in stock, though it can be ordered online. The TF-100 is a better deal.

 

[Yankintx]

FYI, none of the Leslie's kits have the FAS/DPD Chlorine test, but you can add just that kit from tftestkits.net. Otherwise, just order the full TF-100 or K-2006 from the site. You'll have it in a couple of days in my experience.

I found that out the hard way after buying the Leslie delux kit....dpd only. I can't get accurate high fc readings without titrations right?

 

[chem geek]

That's right. You can dilute the water sample with distilled water so you can read the chlorine level with your DPD test, but that reduces the precision. Also, the DPD test itself isn't as precise as the FAS-DPD test even when the chlorine level is in the range of the test -- unless you get very used to how to read the test. You can get just the FAS-DPD chlorine test by itself at TFTestkits.