Help with high combined chlorine!

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Mr. Scott

Mr. Scott

Member
Aug 4, 2019
18
NJ
Hi, I have been a long time lurker and have used the BBB method for several years without issue, until now.

Over the course of the summer I have had a slowly rising CC level, but all the other levels held pretty constant. PH at 7.3, TA at 80, CYA at 30. Two days ago after the CC reached .80 PPM, I shocked my pool using the 10x method to burn off the CC, 17 gallons of 12.5% bleach which backfired horribly. My CC has skyrocketed to nearly 2 PPM, my CYA and TA dropped to single didgits, my PH raised to 8.2, and my FC level will not go above 2.5 PPM with CC at 4.3 PPM. The water is unswimable now and my family is pretty mad at me right now. Searching online, I found out the 10x method is wrong, despite being advised everywhere on the net. I got a test kit for ammonia and it indicates there is none in my water, yet I still have ultra high CC levels. What can I do now? I know I really screwed up this time. Thanks in advance for any assistance.
 
Welcome to the forum.
How are you testing? Your CYA and TA would not be effected by adding sodium hypochlorite.
 
17 gallons of 12.5% raised your FC by 71ppm. You must let that drop before your testing is valid.
 
ColorQ, I have been using it for several years. I figure it is probably the high chlorine level in the pool messing up the other readings. As of now, the water is very itchy and reeks of chlorine, despite a FCL of 2.46. My CCL has risen to 4.30 with my latest test. Water has been crystal clear all summer and still is.
 
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Donldson said:
Your FC is NOT 2.5 after dumping in all that chlorine. Your tester can't deal with the chlorine level in your water and is spitting out garbage numbers as a result.
Click to expand...

I was afraid of something like that. Should I just shut off my bleach feeder and not add any more chlorine for awhile?

Also I do have solar panels, is it possible for some sort of contamination to be inside of them? Since I shock at night, it would not normally circulate through them, something I didn't think of until recently.
 
I don't know about solar panels but we don't "shock", we slam but only if needed, not as a planned event. Keep FC in line with CYA and will not need to shock to kill an algae bloom. It won't start in the first place. ?
 
I have not had any algae all summer. Just kept the FC above 2.2 PPM with CYA around 30. I only tried shocking/slamming after my CC was getting high and the water was becoming a tad itchy, I don't do it as a normal routine. The stupid 10x approach made things worse.
 
Ok, sorry. Just wanted to make sure all on same page. Some use shock and slam interchageably and that causes confusion.?

About the 2.2 FC...that is very close to the minimum so any little issue, swimmer load, organics in pool etc could easily cause a drop allowing algae to start up.

If CYA is about 30 then it could easily be 35 or more? Minimum is now 3ppm.

Sorry, not trying to brow beat, but 2.2 would make me very nervous allowing for subjective cya reading and probably + or - .5 on FC test accuracy.

Good luck on your mission!?
 
Thanks, I have had a hard time keeping my FC at 2.5, not sure if its my tester or something been eating a lot of chlorine. My pool has been taking over a gallon of 12.5% a day to keep it above 2.2 FC this summer. Last reading I took today is 2.45, but that is probably not accurate with the amount of chlorine I added.

Only me and one other person uses the pool, both of us get out often to use the restroom. We do use a lot of sunscreen, mostly the clear spray stuff. Have been noticing more of a scum line than previous years. Hopefully the neighbors have not been visiting my pool when we are not home, LOL. The pool is on the edge of the woods with large trees.

Should I add some water to dilute the high chlorine levels?
 
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Hi Mr. Scott, welcome to TFP!

I feel like you might be well served to read up about TFP methods. It sounds like you have a slightly different understanding about a number of things.

First, please read ABCs of Pool Water Chemistry in Pool School. There are lots of other articles in Pool School that will help you understand many things as well.

At TFP, we don't shock with 10x chlorine. We use the SLAM Process. This video will augment your reading about the SLAM Process.




Your high CC is the result of all that chlorine attacking and killing something organic. When there's nothing to kill, your CC will go back to 0. We don't try to control CC, but rather use it as a guide to tell us what's happening in the water. The reason your pool has an odor is because you're smelling the CC (chloramines). Something is surely being killed, and that is good. You will need to keep that high FC level maintained to get ahead of it. Which is why we SLAM (Shock Level and Maintain) rather than just dumping chlorine in one time and expecting it to do the trick.

I don't see a CYA test result, but you said single digits. Could you post a full set of test results please? Note that your pH test result at FC over 10ppm will be inaccurate and as noted above, your FC reading is clearly wrong as well, but you can post them in this format anyway.

FC
CC
pH
TA
CH
CYA

Hope this helps you understand TFP methods. If you follow the guidelines here, your pool will be fixed up in no time. Promise!
 
Before 10x shocking with ColorQ DPD testing.

FC 2.39 Difficult time getting it much higher with the breach feeder near max.

CC .70

PH 7.3

TA 80

CH 400

CYA 31

Next day after 10x shocking with ColorQ DPD testing, probably inaccurate.

FC 2.45

CC 1.03

PH 8.2

TA 5

CH N/A

CYA 5

I did the 10x shock a few years ago and it worked like a charm, this time not so much. When you search online for BBB shocking, the incorrect 10x shocking method is what mostly comes up. I only found information about it being wrong yesterday 6 pages into the search list. It is terrible, sunny and 90 degrees out, water is warm, but un-swim able, fear I may have ruined the pool for the season, the water burns. Feel like such a fool now.

Should I continue slamming the pool by adding chlorine or should I stop and add water to delute the water and make it swimable again? I blew a lot of money on the chlorine and I am low on money for any more chemicals. I do not use overpriced pool store stuff, just plain BBB method chemicals. Should I get one of those FAS-DPD test kits, I can only probably afford just the chlorine testing version, not the complete kit.

This is an older gunite pool built back in 1973 that was refinished ten years ago. It only has two outputs in the shallow end, skimmer and floor drain are in the deep end.
 
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Yes, by all means get a FAS-DPD kit!! It will let you know what your FC really is, as well as the CC.

I think if I were you, at this point I would drain 50% and refill. That high chlorine is going to make you miserable for days, and draining will let you start a SLAM so much sooner. While you wait for your FAS-DPD kit, screen and vacuum your pool, especially in the nooks and crannies.

We'll get you straightened out!
 
You could probably get away with just buying the DPD powder, R-0871, R-0003, a vial, and a scoop, and I'd also add CYA and a test tube. What gets me wondering is it appears that your testing is all out of whack at your high FC level. CYA did not go down to 5, nor did TA. pH is inaccurate over 10ppm so you can throw that result out. I'm not sure your test kit is serving you well as is.

XL Option
tftestkits.net

R-0003 DPD #3 Reagent

tftestkits.net tftestkits.net
tftestkits.net

TF Graduated Cylinder (Chlorine Only)

tftestkits.net tftestkits.net
tftestkits.net

Scoop for R-0870 DPD Powder (0.05g)

tftestkits.net tftestkits.net

If you add CYA, here's what you need.
tftestkits.net

R-0013 CYA Reagent (8oz)

tftestkits.net tftestkits.net
tftestkits.net

CYA View Tube (BIG TF-100 Size)

tftestkits.net tftestkits.net

Note however that these items by themselves are close to the price of a new test kit with fresh reagents. Or, if you don't need the hardware (mixing bottles/vials, etc.) you could buy a TF-100 refill and get fresh reagents. I'd add a .25 scoop and a laminated instruction card to the refill if you go with that option.

tftestkits.net

TF-100 Refill Set

tftestkits.net tftestkits.net
tftestkits.net

TF-100 Laminated Instruction Card

tftestkits.net tftestkits.net
 
Do you have one of the cheap yellow chlorine tests? Since that test doesn't bleach out it would at least confirm to you that the ColorQ is not reading correctly.

And Marty is very correct: 10x 0.8 is 8, which would have been 1.7 gallons of 12.5%, not 17. You did a "100x shock", if such a thing existed.
 
If getting the water out of the pool is the only hang up, you could always rent or buy a sump pump to pump over the side.

Or do you mean you don't have a place for the water to go or no fill water available?
 

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