I'm going into shock!

[riseandrun]

Hi everybody,
First off my test results.
FC .5
CC.5
PH 7.2
TA 70-80
CYA 0 (I'm using Sod. Hypo for sanitizer)
CH 300-400
All of a sudden I can't keep chlorine in the pool. I need to be 4-5ppm because of my temp. Literally a gallon of shock yesterday morning. The water is a "tad" cloudy as well. I posted a while before about a similiar problem, but discovered with the forums help that my shock was over a year old. This "new stuff" I have has been in a barn for a good part of the summer so maybe that's suspect again. It's been a hot summer here.
Anyway, to shock my pool and keep it open I'm thinking of using Oxy-klear. I have the additional problem of not being able to close the pool during the shock process (If I can help it) and my pool guy told me that Oxy-Klear was a non-chlorinating shock. Just wondered what the pro's think.
Also would it be beneficial to me at all to try and get my CYA up with my triclor tabs to about 20 or so? Lastly I can't find what OCLT stands for. (hope it's not obvious)
As always thanks for the help!
KW

 

[kimkats]

OCLT=Overnight Chlorine Loss Test
pool-school/overnight_fc_test

VERY useful to see if there is anything going on. BUT I would say your pool DOES have something going on with the loss of FC and cloudy.

I would go buy a LOT of bleach/chlorine and start the shock PROCESS. (See my siggy for the link.)

How are you testing?

Kim

 

[riseandrun]

Thanks Kim,
I knew that as soon as I asked it would become obvious what OCLT meant.
I'm testing with my Kf-100 test kit with the spoon full of R-870. Can't get more exact than that right?
I just threw in the Oxy-Klear 2 lbs. and turned my auto-matic chlorinator with the pucks and I'm going to see how it looks on Monday and will report back. I have a guy coming by tomorrow to test the pool and I'll see what he measures in the morning.
Thanks for the reply Kim.
KW

 

[chem geek]

It sounds like your not having any CYA in the water had the chlorine get broken down by sunlight to quickly. Why is the CYA 0? I see from your signature that this an indoor pool (even for an indoor pool a low level of CYA around 20 ppm is beneficial)? Oh wait...I just looked up from your earlier posts that this is a commercial pool so you may not be allowed to have any CYA in the pool depending on state regs. Darn. I suggest you add "commercial pool" to your signature so this doesn't come up again.

The OCLT will tell you if you've got a chlorine demand, but since the water is turning cloudy I suspect that's algae starting to grow because the FC got too low (probably to zero in some parts of the pool if you are only measuring 0.5 ppm). However, unless you have a lot of light on the pool, algae doesn't grow that as fast indoors (but if you've got lots of windows or bright lights, then it can certainly grow). Sounds like you may need to shock, but because the pool is indoors you'll probably have to dechlorinate some to get the FC back down after you kill off what's growing.

Also, check your filtration system to make sure it's working properly.

 

[riseandrun]

More info on my pool in addition to it being a commercial pool (check out my signature ) I don't get any direct sunlight at all but I do get lot's of light. My North wall is about 35% windows under a deck on the 2nd floor. I didn't read anywhere in the OCLT test that temperature makes a difference. I thought that the heat burns off the chlorine faster. I'm just trying to increase my knowledge here not questioning someone's experience.
It's interesting to me that you mention the filtration system because I almost always have a 10 lb. pressure difference between the input and output. I read in my state certification booklet that at 12lb difference I would need to backwash. I even changed one of the guages because I thought maybe it didn't work. Every time I've backwashed the inspection window at the top is always clear. I had a pool place come out and change the sand in my filter about a year ago since I am new to pool maintenance and maintaining a pool at all.
As always input is good.
Thanks chem geek.
By the way, my CYA is ok up to 50 ppm

 

[chem geek]

Yes, you are right that temperature does affect the rate of chlorine loss from everything but sunlight. So the OCLT reading will be affected by temperature. However, I don't think it will be so much of a difference to have you go over 1 ppm FC in 8-hours.