New Pool Owner - Need Help

[Brian_b]

We just moved into a house over the weekend with an in-ground concrete pool (Dallas/Fort Worth Area). It's chlorine and about 17,000 gallons. I've read through the pool school threads over the past couple weeks, ordered a Taylor k2006 test kit and all of the basic chemicals.

The water to the pool is very clear, however before we moved the skimmers were full of 3" tablets as well as the inline filter. I tested the water last night and pH was low (7.1) and CYA was very high (over 110) and FC came in around 19. Total Chlorine was about 1ppm. I also ran a diluted test for CYA to confirm. I added some borax to bring up the pH last night and now I'm trying to figure out the game plan on what to do next with such a high CYA and FC level (but still clear water).

I took a sample to the local pool shop to confirm and their numbers were as follows (very close to mine, so that's good I guess):

TA:57
pH: 7.5
CH: 361
FC: 19.07
CYA: 127
Phosphates: 2493

The water is still clear, however I'm not sure where to go next. Do I need to drain the pool? Is it safe to swim with such high CYA and Chlorine and Phosphate levels? The pool is in full sun and it's well over 100 here every day with no rain for the foreseeable future. I've gotten rid of the tablets and have liquid chlorine. Pool Math states that my FC should be around 14 with these CYA levels. Is this correct? What is an ideal FC level with a CYA level this high? Ideally I can make it through the next couple months with the kids being able to swim before draining or maybe evaporation and adding fresh water would help. Any real downside to that or do I just need to bite the bullet and drain it this weekend.

Thanks for any advice. This forum has been a huge help!

 

[Rancho Cost-a-Lotta]

Welcome to TFP Brian!

Congrats on the new pool and the house that came with it!

You made the right move by removing tablets. A CYA level of 120 ppm is high, too high to manage. With a CYA of 120, the minimum FC level is 9 ppm and target range is 13-15 ppm. You can swim up to FC SLAM level 47 ppm. The problem is that pH test is not valid with FC levels above 10 ppm. You may be able to manage for a while by allowing FC to drop to 10 ppm to test pH, then bumping FC back to target level.

In the future, ignore pool store results and post your own.

CYA won't leave the pool through evaporation. It will drop slowly on it's own, but you need to do a water exchange. Consider a no drain water exchange. Doing a traditional drain and refill this time of year is not advisable.

Draining - Further Reading

www.troublefreepool.com

 

[Rancho Cost-a-Lotta]

I forgot to address one of your concerns. Don't worry about phosphates. As long as you maintain proper FC/CYA ratio, phosphates generally won't make a difference.

How is your TA level?

One way you could get around testing for pH is to purchase a reliable pH meter. Search here for recommendations. Our experts have previously recommended Apera meters

 

[Brian_b]

I forgot to address one of your concerns. Don't worry about phosphates. As long as you maintain proper FC/CYA ratio, phosphates generally won't make a difference.

How is your TA level?

One way you could get around testing for pH is to purchase a reliable pH meter. Search here for recommendations. Our experts have previously recommended Apera meters

Rancho,

Thanks so much for the helpful information. I'll do some research on the no drain water exchange and look into that as an option as well as keeping the CYA and FC ratios as in line as I can.

My TA level was at 60ppm when I tested with the Taylor kit. My understanding is that is in-spec.

I'll also look into a pH meter for sometime in the future.

Thanks!

 

[Rancho Cost-a-Lotta]

I'll also look into a pH meter for sometime in the future.

Okay. Just test pH when FC is 10 ppm or less. TA is good!

 

[Brian_b]

Okay. Just test pH when FC is 10 ppm or less. TA is good!

Will do! Thanks for the help.