Chlorine too high...not sure why...?

[DanaSC]

FC: 10
CC: 0
TC: 13
pH: 7.5
TA: 90
CH: 240
CYA: 70


So I tested the water a couple of days ago and chlorine was at 13. Today it's at 10. We have only been using pucks and there was no reason for the pool to be at 13 the other day with only one puck in our skimmer. It was the 26th when it was at 13, so that's, what, almost 4 days ago and it's only come down 3ppm...

Does this seem strange to anyone? Normally our pool holds around 4-6 with pucks, so this seems really odd to me and my husband says he didn't add any chlorine to the water. We haven't shocked or anything. Thoughts?

 

[Tanker]

First off, double check your readings. FC of 10, CC of 0 and TC of 13 can't be right.

 

[duraleigh]

As the weather (and pool water) cools, you chlorine usage drops way down.

I know you didn't ask, but you should stop using the pucks as your CYA is already too high and will only get worse if you stay with pucks.

 

[Shirker]

This does not really answer your question, but when I was using pucks, I had a hard time hitting my FC goals because there were too many variables to control for. I had to monitor the feeder dial, water temp, and pump run time. Switching liquid chlorine made it a lot easier. I knew exactly how much was being added (as apposed to guessing how fast the pucks were dissolving) and knew exactly how the chemical profile of the water would change.

 

[timerguy]

She didn't fix the result from the other day when her FC was 13. What testkit are you using? And, it's been pretty cool here lately. And yes, you need to stop using the pucks!

 

[jblizzle]

I would also point out that putting pucks in the skimmer is in general a bad idea due to how acidic they are ... especially if you are not running your pump 24/7.

FYI according to the FC/CYA Chart, with a CYA of 70ppm, your minimum FC level is now 5ppm and your likely want to target around 8ppm ... so your FC is really not that high.

 

[tim5055]

I'm in Lex also and my chlorine usage has fallen off. Daily testing is the key.

 

[DanaSC]

Thank you all! First, it's true, I miswrote the numbers - it should have said TC is 10. Second, I definitely know we shouldn't use pucks, but for daily chlorine that is what we use because we've got 2 children under 4 and I forget to add bleach to the pool too often, so the pucks have helped us not get algae. I do use bleach for shocking (taking pucks out), etc, though. And you all are probably right - with the cooler temps, etc., that probably explains why it hasn't dropped back down as fast as I've been used to. I just "felt" like something wasn't right that the chlorine had gotten so high in the first place. And you're right - with the CYA of 70, 10 isn't so bad, but that 13 threw me because with only one puck in the skimmer, 13 is a higher read than I normally get. So I thought maybe there was some anomaly that maybe you would know of. Wish I was better at remembering to put chlorine in every other day or so, but I'm just terrible at it and we've paid for it dearly. We have well water, so at the beginning of the season we drain the pool down about halfway or so and fill it back up. One of these years we'll get an automatic chlorinator thing, but not yet.

 

[timerguy]

You're a prime candidate for either a stenner pump or swg. We could help you better if we had some answers to the questions I asked earlier. How (what test kit are you using to test your water) or who (Leslie's?) is testing your water? We could also use some current test results If you have them. You should be testing FC/CC and pH daily that's why we highly recommend you get a good test kit, either the Tf-100 or Taylor k-2006, both of which can be ordered at tftestkits.net. You can get by with all the other tests weekly-- once you get your cya under control, you can test that monthly or when there's a large change of water levels.

 

[tim5055]

Thank you all! First, it's true, I miswrote the numbers - it should have said TC is 10. Second, I definitely know we shouldn't use pucks, but for daily chlorine that is what we use because we've got 2 children under 4 and I forget to add bleach to the pool too often, so the pucks have helped us not get algae. I do use bleach for shocking (taking pucks out), etc, though. And you all are probably right - with the cooler temps, etc., that probably explains why it hasn't dropped back down as fast as I've been used to. I just "felt" like something wasn't right that the chlorine had gotten so high in the first place. And you're right - with the CYA of 70, 10 isn't so bad, but that 13 threw me because with only one puck in the skimmer, 13 is a higher read than I normally get. So I thought maybe there was some anomaly that maybe you would know of. Wish I was better at remembering to put chlorine in every other day or so, but I'm just terrible at it and we've paid for it dearly. We have well water, so at the beginning of the season we drain the pool down about halfway or so and fill it back up. One of these years we'll get an automatic chlorinator thing, but not yet.

Dana,

You say three things here that make me uncomfortable:

1. "I definitely know we shouldn't use pucks" You understand the problem with this one, I probably don't need to go any further.

2. "I do use bleach for shocking" If you follow TFP and keep your FC where it shold be relative to CYA you should never have to shock your pool.

3. "with only one puck in the skimmer" This one is doing damage to your pool unless you run your pump 24/7. With a puck in the skimmer it dissolves all the time. So, when the pump shuts off the puck just sits in the skimmer continuing to dissolve "superchlorinating" the water in the plastic skimmer. This superchlorinated water degrades the plastic. If you continue to keep a puck there eventually the skimmer plastic will become brittle and fail. If you are going to use pucks, at least get a floater and let it float around the pool.

 

[YippeeSkippy]

I think another problem with a puck in the skimmer basket, if the pump isn't run around the clock the water in the basket area becomes very acidic. Then when the pump does get turned on, that super acidic water then blasts into the pump and might be damaging.