Chlorine level really high, won't come down.......

Gravel7

Active member
Jun 21, 2011
25
Hello,
I don't have any experience with pools and have a question about my chlorine level. I installed my pool at the end of June. Did the new water stabilization process....brought a sample to the local pool store and they told me how much to add of what.......Since then I have been just placing a 3" chlorine tablet in my skimmer. 1 Tablet a day. Most of the time there would be a tiny bit of yesterdays tablet left when I add the new tablet, sometimes yesterdays tablet would be completely gone. I also would shock the pool once a week with about 1/2 gallon of shock....per their recommendation. Everything seems great.
I have been very lazy on my testing. Mostly because the water has been, and still is, crystal clear. 1 week ago I tested the chlorine and ph levels using the cheap little testing kit that came with the pool. Not the strips, its an add 4 drops of this solution to here.........
My chlorine level was way off the chart, high. PH was high too. I stopped adding chlorine to let the level come down. Tested it a couple days later....still of the chart. A couple days after that.....still off the chart. Its been 7 or 8 days and it is still reading really high......off the chart still, but not as bad. Ph is still high to. The water has a bit of a chlorine sent, just like other pools I've been to......

Why won't the chlorine level come down? What should I do? I can't believe its been a week and still so high. I'm fine with just waiting it out, but not sure if its the right thing for me to do.

Thanks for any advice!
 

Bama Rambler

Mod Squad
TFP Expert
Bronze Supporter
LifeTime Supporter
Jun 22, 2009
24,193
SouthWest Alabama
Ditto what Scott said. With the test kit you have, you really don't know what your numbers are. Since the kit you have tests total chlorine you don't know if what you're testing is FC or CC or some combination. Your pool shouldn't have a 'smell' when it's properly sanitized.
 

Beamup

LifeTime Supporter
Aug 28, 2010
176
Boston, MA
Third that. The real killer is that you don't know your CYA level, which means that your FC can be "way off the chart high" according to the simple test but still too low to stop algae blooms or keep the pool adequately sanitized. Assuming the pucks are 8 oz and you've added 45 of them, that would be 111 ppm CYA and would require you to maintain FC no lower than 8 or so, while the simple tests can only go up to 5.

You will likely have to drain and refill to get that CYA down to a workable level, then stop using the pucks and start using liquid exclusively.
 

Patrick_B

TFP Expert
LifeTime Supporter
Jun 7, 2011
15,006
Midland TX
Yes, the most important thing now is a good test kit. You really ought to have a full kit of good quality. You obviously care enough about your pool, and it will help you trmendously. The TF100, or the Taylor K 2006 would fit.the bill. Good luck, and welcome to TFP.
 

Gravel7

Active member
Jun 21, 2011
25
Thanks for the replies. Yes, I will have to look into the TF100.
Heading over to the Pool School section this afternoon.

Thanks again!!
 

anonapersona

TFP Expert
LifeTime Supporter
Nov 5, 2008
2,598
We can calculate what you CYA level might be. Exactly how many tablets have you used, days since filing the pool? Can you weigh a tablet or several on a kitchen scale that reads ounces? At the bottom of the Pool Calculator you can input your info, maybe 50 days times 7oz is 350 oz of trichlor in 13,530 gallon pool gives CYA of 108, if poolwater volume is less (check actual water depth), could be 115. Less some for splashout, maybe.



Were there any other chemicals added along the way? "Liquid shock" has no CYA
 

Gravel7

Active member
Jun 21, 2011
25
I never added anything else. Basically just one 3" tablet a day and 1/2 gallon of shock weekly.
I can't believe that the water isn't begging for chlorine yet. I must have been over doing it bigtime? I did exactly what I was told to do with the tablets and shock........
I think i'll be ordering one of the test kits that Brushpup mentioned tonight. And reading the pool school once I get caught up here at work.

My wife has a couple friends over right now, each with 2 kids. Plus my 2. 6 kids splashing around all day today. Well, the water is crystal clear with an extremely light hint of chlorine scent......as long as knowone shows up with a test kit, I won't be embarrassed. :-D
 

anonapersona

TFP Expert
LifeTime Supporter
Nov 5, 2008
2,598
As you read through Pool School, take note of the Chlorine/CYA chart (and bookmark it). You will notice that for CYA in the 100 range, you need to never go below 7 ppm FC and up to near 12, though it is OK to swim up to shock level of 39. Your test kit reads that as "over the top high" when above 5 so you may actually be at a perfect FC level and not be able to test for it.

For now, until the FAS-DPD kit arrives that can test accurately at those levels, you can dilute the pool water with distilled or RO water (no chlorine). Use 2 parts distilled and 1 part pool water. Then multiply by 3. Since you are hoping to keep FC in the 7 to 12 ppm range, when it is on target you will read it as 2+ppm to 4 ppm when diluted. Not accurate but better than "out of range = unknown".

If it still reads Out of Range, you can, if you want, test again at 3 distilled + 1 pool and multiply by 4. As long as you are at less than 39 ppm actual FC, assuming a calculated CYA of 100-ish, you can swim with no damage to kids or pool. Odds are that you not near shock level at all and so I think this is not necessary to do. But keeping it at or above 7 ppm is very important, or better above 8 ppm since we don't know CYA for sure.

[EDIT ... No, this part is wrong -- see Chem Geek later]You will want to deal with the high pH [wrong -- pH cannot be trusted when FC is above 10 ppm, yours may be above 10 ppm ] with a bit of muriatic acid, allowing at least an hour before letting the kids back in the pool. Adjust pH to about 7.5, using the Pool Calculator to determine the amount of acid to get you from where you are to 7.5. Read Pool School for details, generally, handle with extreme care (eye protection) and mix well after adding to pool.
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,083
San Rafael, CA USA
One 8-ounce Trichlor tablet per day in 13,530 gallons would add 4 ppm FC and 2.5 ppm CYA so over one month that would be 75 ppm CYA. Since it's been somewhat over one month, your CYA may be closer to 100 ppm now.

Usually, the chlorine loss rate a medium-level CYA is around 2 ppm FC per day so you've been adding about twice as much as needed, at least after the first week or so. The shock just added even more chlorine. 1/2 gallon of 10% chlorinating liquid in 13,530 would add 3.7 ppm FC and you said you were adding that once a week.

Even worse, however, is that you didn't mention adding any pH Up product to compensate for the pH. Trichlor is very acidic and the amount you are adding would lower the Total Alkalinity (TA) by a large amount and the pH as well. I suspect your TA may be near 0 now and your pH might be below 6. You reported your pH being high, but unless you added pH Up or equivalent product to compensate for the pH, it is likely to be very low.
 

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Gravel7

Active member
Jun 21, 2011
25
I bought them at Sams Club. 5 gallon bucket of them. When I get home from work I'll take a look at the specifics. All I remember right now is "3" stabilized chlorine tablets".
 

anonapersona

TFP Expert
LifeTime Supporter
Nov 5, 2008
2,598
Gravel7, please note that chem geek is correct about pH being possibly lower than your reading.

You will want to do the diluted test for FC and test pH. Report back when you get the FC test, while pH will be incorrect above FC=10 it may not be terribly wrong.
 
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