SLAMing and Chlorine level went TOO high!! WHY??

[timmco]

Living in North Texas the weather is warming up! I am trying to "open" our pool. I started to SLAM yesterday. I vacuumed the pool by hand, cleaned filter and tested chemicals.
Which were:
FC 5.5
pH 7.8
TA 60
CYA 45

I added acid to bring the pH down to about 7.2

According to the SLAM/CYA chart I needed to raise my FC to 18. It said to add 3.5 gallons of chlorine. I added 3.5 gallons of 10%.
The filter has been running for about 15 hours straight. I checked FC level again and it was 25!!!!!! I checked it 3 times!! ranged between 24-26.
I take my water samples about 18" below the water surface and away from jets.
This happened a few times last year when I was just doing my regular every other day test/add.

This is my third year doing the TFP method. The first year my pool was immaculate! Last year I could never get the levels to stay as consistent. The start of this year is not going great!

Am I testing wrong? Do I need new test chemicals? What is going on here?

Thanks for your input!

 

[mknauss]

Do I need new test chemicals?

How old are the reagents? TFTestkits has its Spring sale on for a complete refill.

Testing error, pool volume, bleach strength, etc. Your target SLAM level FC is 20 ppm if your CYA is 50 ppm (you cannot measure a 45 ppm CYA - round up).

 

[mknauss]

Also, do you need to follow the SLAM Process? Did you do an Overnight Chlorine Loss Test?

 

[Jimrahbe]

Tim,

I am not sure of the problem, but assume you do not close your pool in the winter here is Texas. If so, there is almost no reason to SLAM. I have three saltwater pools and in 10 years I have never had to perform a SLAM. As a moderator it is almost embarrassing to say I have no SLAM experience.

Why are you SLAMing?? What is the actual problem?

Thanks,

Jim R.

 

[PoolStored]

Am I testing wrong? Do I need new test chemicals? What is going on here?

It may be that you have some stratification of water, seems odd after 15 hours of running the pump, but possible. Do you have a robot? You might throw that in the pool and let it run, should help mix the water vertically.

 

[Newdude]

As a moderator it is almost embarrassing to say I have no SLAM experience.

Orrrrrrrrrrr, is that just a testament to following the program and how well it works.

 

[woodyp]

Doing a little math in Pool Math.....adding 3.5 gallons of 10% would only raise your 27,000 gallons by 13. 13+ existing 5.5 doesn't come up to 25.

 

[timmco]

How old are the reagents? TFTestkits has its Spring sale on for a complete refill.

Testing error, pool volume, bleach strength, etc. Your target SLAM level FC is 20 ppm if your CYA is 50 ppm (you cannot measure a 45 ppm CYA - round up).

Some of the reagents are 2 years old, some are 1 year.
Good to know about the CYA. I figured since it was smack dap in the middle of 40 and 50

 

[timmco]

Tim,

I am not sure of the problem, but assume you do not close your pool in the winter here is Texas. If so, there is almost no reason to SLAM. I have three saltwater pools and in 10 years I have never had to perform a SLAM. As a moderator it is almost embarrassing to say I have no SLAM experience.

Why are you SLAMing?? What is the actual problem?

Thanks,

Jim R.

We don't technically close the pool, however, it does get neglected somewhat. It had developed some algae and the water was cloudy. A few weeks ago, I tried just cleaning it out real good, cleaned the filters, and balanced the chemicals etc. but the water still looked cloudy.

 

[timmco]

It may be that you have some stratification of water, seems odd after 15 hours of running the pump, but possible. Do you have a robot? You might throw that in the pool and let it run, should help mix the water vertically.

I have 2 fountains that mix the water real good. I do have an old pressure side cleaner that usually stays in the pool and runs every day.

 

[timmco]

Doing a little math in Pool Math.....adding 3.5 gallons of 10% would only raise your 27,000 gallons by 13. 13+ existing 5.5 doesn't come up to 25.

Exactly. That's why I'm maybe wondering if my reagents are bad?? or what is going on. I don't think I'm testing wrong? I'm doing it the same exact way I did the first year with no problems.

 

[Jimrahbe]

Tim,

If you have visible algae, then you need to SLAM. I must have missed that info in your original post.

Once you get visible algae, you can't just "clean things up", you have to SLAM.

I suspect you are beginning to see that just a little effort in the winter will save you a whole lot of time in the spring...

Thanks,

Jim R.

 

[timmco]

Tim,

If you have visible algae, then you need to SLAM. I must have missed that info in your original post.

Once you get visible algae, you can't just "clean things up", you have to SLAM.

I suspect you are beginning to see that just a little effort in the winter will save you a whole lot of time in the spring...

Thanks,

Jim R.

Yes, that is why I decided to SLAM. and YES I do see that now to do some effort in the winter!

 

[woodyp]

Reagents are guaranteed for ONE year even though some will go longer.