Trying to get the CYA under control.

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About 2 years ago, I was talking with a guy at work and he said that his wife put Shock (Cal Hypo) in their chlorinator and it basically melted the chlorinator insides from all the heat. The exothermic reaction was enough to destroy their chlorinator. The reaction is easily handled by thousands of gallons of water but not in a small confined space. These chemicals have the potential to cause serious issues if not handled properly.
Do not pour Cal hypo or anything else into the chlorinator.

Explosions? I don't know, but I wouldn't want to try. Especially in a commercial/public pool.
 
I took a sample last night after the Sun was down 7:00PM, but still light to do a OCLT, the FC was 8 ppm, this morning I before the Sun was up, but again it was light out 6:30AM. and it was 4ppm. A post earlier in this thread indicated that if my ppm dropped more than 1ppm there was something besides Sun eating my FC. What is my next step, should I slam it with Chlorine? The bottom of the pool looks stained from dirt, I'm not sure if it was there before and I can just see it now because the water is so clear or if this is something that has developed since the dilution.

the other numbers are the same as posted earlier.

FC: 4.0
CC: 0.5
CH: 275
TA: 120
Ph: 7.4
CYA: 65
 
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I know I keep asking this same question, but I need to be sure that's what I need to do. Although I don't see in the SLAM instructions where it said, my assumption is I would have to close the pool for a minimum of another day, maybe more.

I did a OCLT the last one was just my usual samples, I paid special attention to the details this time. When I closed the pool at 7:00PM I noticed that the Sun was still up a little, I took my usual sample and added chlorine, at 9:30PM, well after the Sun was down, the FC was at a 9.5ppm. I just took another sample at 5:00AM, With the Sun out of the equation totally it was a 7.5. So that is a 2.0ppm drop in 7 1/2 hours. The water is crystal clear, and the CC tests from 0.0 - 0.5. Should I SLAM it? After having the pool closed for 3 weeks already, I really don't want to have to close the pool again, but if it's what I need to do to get it under control then so be it.

Thanks guys, I know I am being a needy Noob right now, I promise it won't always be like this LOL
 

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A residential pool does not need to be 'closed' to SLAM. Not sure about your situation.

We would suggest that a SLAM is necessary with that FC drop over night.
 
To expand on what Marty said, it is safe to swim in water with FC up to SLAM levels in our residential pools. And you can see clearly to the deep end and pH is within range. The active chlorine level will still be below a pool with zero CYA and 3ppm FC.

At SLAM levels, I doubt the guests will know the difference. The FC won’t harm people or clothes. They will be happy the pool is clear, clean and cool.

Your Health Dept may have regulations limiting you and we have no way of knowing what those are.
You will need to decide how to proceed with this information.
 
Teald024 said:
To expand on what Marty said, it is safe to swim in water with FC up to SLAM levels in our residential pools. And you can see clearly to the deep end and pH is within range. The active chlorine level will still be below a pool with zero CYA and 3ppm FC.

At SLAM levels, I doubt the guests will know the difference. The FC won’t harm people or clothes. They will be happy the pool is clear, clean and cool.

Your Health Dept may have regulations limiting you and we have no way of knowing what those are.
You will need to decide how to proceed with this information.
Click to expand...

I have read extensively on the health department requirements, all they reall care about is if the CYA is under 100, that the FC is at or above the appropriate levels for the CYA level and that the Ph is above 7.0 and below 8.0. It does say with CYA the CH should be between 2.0 and 10.0, under the section on shock it doesn't say either way if it can be used. Wouldn't it make it harder to maintain shock levels if the pool is in use?
 
You will have more FC loss due to use but it should not be appreciable as long as no one adds urine or other contaminants to the pool. Your CC will spike if urine is released in the pool.

If you are confident in your standards there is no reason to close the pool to use as long you meet the pH and clarity requirements and do not exceed the SLAM FC level.
 
Thanks. there were a couple of people in the pool when I went to check the FC level 3 hours after the initial dose, and I asked them how the water was, they said it was great, I asked if it seemed like there was a lot of chlorine and they said no they couldn't even tell. Words not out that the pool is opened again so no urine spikes in the CC, but that might be why it spiked they other day. Had to raise the FC to 26 3 hours later it had dropped to 12.5 and boosted it back up, will check and adjust at 4:00, then again after I close it at 7:00, or maybe I'll wait till 8:00 after the Sun is completely down and then that will be the basis for my Over Night Chlorine Drop Test.

I have convinced them to get an auto liquid chlorine feeder instead of using the trichlor feeder. I tried to get them to go with the SWG system, but they're okay with the extra expense in the long run.

I'd really like to thank all you guys for so much help, you have been an invaluable resource. I was so lost when this all began, and with all your help I and really getting a handle on this, and feel more confident in what I have taken on here.
 
Testing error can come into play at elevated FC levels. So if you have crystal clear water for multiple days but you are just not passing the FC loss of 1 ppm or less, then we recommend you let the FC drop to 10 or 15 ppm and run the OCLT.

But this is after multiple days of trying to pass the OCLT.

Sunscreen and lotions have minimal effect on FC loss. They make scum lines and plug up filters.
 
mknauss said:
Testing error can come into play at elevated FC levels. So if you have crystal clear water for multiple days but you are just not passing the FC loss of 1 ppm or less, then we recommend you let the FC drop to 10 or 15 ppm and run the OCLT.
Click to expand...

The Pool has always been crystal clear, and aside from 1 CC test it has always been 0.5 or less. The only condition I can't seem to pass is the OCTL. I'm curious it the Sun (as in UV rays) that eats the FC, or is it the heat? because it has been very hot here the last few weeks, highs of 100+, and lows of high 70's to low 80's. I'm in So. Cal.
 
Sun and organics are what consume chlorine. So once the sun leaves the pool surface, it is only organics.
 

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