Newbie with high FC

[mark1gb]

Hi all and thanks for all the great info on this forum and site!
Brand new to pool ownership and just had a new Fiberglass pool installed - yet to have the orientation from my Pool Builder or any guidance on equipment, so using all the info here and the TF Pro test kit to try figure it out myself.

It looks like the SWG was set by builder to 60% and pump to run for 12 hours.
My initial test with the TF test kit had FC 2.5, CYA 35.
I brought the CYA up to 75 and left everything else the same.

A week later have tested again and FC is up to 18 whereas my target is 6-11.
Firstly, is it safe to swim at 18 FC while I work to get it down? (have a 2 year old and 5month old at home!)

Then, what are your suggestions for bringing down the FC? The pool is in NJ and gets full sun all day, so presumably if I drop the SWG % right down to something like 10% it will bring the FC down quite quickly? I could also reduce pump operating time by a few hours a day? Or a combination of both

Full test results below - have also just added dry acid per recommendation of pool math app to try bring TA and pH down. Thanks for all your help and advice!

FC 18
CC 0
pH 8.2
TA 100
CYA 75
CH 150
Salt 4500ppm

 

[PoolStored]

Firstly, is it safe to swim at 18 FC while I work to get it down?

You are safe to swim up to (CYA/10)*4. Always round your CYA up to the next 10. Your CYA is 80. Max swim FC for 80 CYA is 32. Oh...and you need to see the bottom of the deep end to be safe.

Then, what are your suggestions for bringing down the FC?

Turn off the SWCG and wait. Test FC daily.
When it comes down to range, then reset the % output and runtime to produce 3ppm FC per day. You can find your ranges here...Link-->FC/CYA Levels
Run for a day or two and adjust based on demand.

Lower your pH using muriatic acid. Lower in .4 increments, test 30 minutes after addition.

Test for but ignore adjusting TA.
When TA > 80, lower pH to 7.6, this will also lower TA. It will rise on its own. When it gets to 8.0, lower again to 7.6.
When TA is between 60 and 80, STOP lowering to 7.6. pH should stabilize between 7.8 and 8.0. pH of 7,8-8.0 is just fine.

Download pool math, configure your pool, enter your SWCG, and use the "effects of adding" function to figure out % output and runtime to produce 3FC. Pool Math link-->PoolMath
Use pool math to track your test results and chemical additions. It will help you with how much to add of each chemical to get the results you want.

Oh...Welcome to TFP!!!

 

[Bperry]

have also just added dry acid per recommendation of pool math app

Dont use dry acid. Its bad for the SWCG and for the pool decking.

 

[mark1gb]

Thanks to you both for the advice and noted on the dry acid. I hadn’t appreciated that dry acid and Muriatic acid were different things!