Free chlorine

[Sonjaraz]

Hi all!
I’ve been testing my pool myself using the Taylor k2006. Happy to be doing this as my results aren’t all over the place like they were with the pool store results. That being said my FC is at 11.5. I’ve got my SWG set at 53% which is clearly too high but is there a way to determine what I should set it at? My CYA is 75. This is the second year with the pool and I don’t think I even thought about changing the setting on the SWG until I started testing own water. Any advice is much appreciated

 

[dfwnoob]

It really isn't too high, necessarily. With a CYA of 80 (the test is not linear, it cannot be interpreted between two values; you must round up), your target FC range is 6-11, so you're just barely off the edge of the range anyway. If it's steady at 11.5, I'd maybe turn it down just a hair so you're still targeting near the high end of the range, though I'm firmly part of #TeamRunHot. Move it down a few percentage points and retest to see where you land.

 

[jimbethesda]

Is it steady at 11.5, or is it growing? The first step is to determine how much your pool loses per day. Do you have the pool math app? You plug in your 27,000 gallons, IC40 cell, 53%, and how many hours you run your pump. That tells you how much chlorine you create every day.

Example: You are creating 3ppm a day in chlorine, and your chlorine levels grow by .5ppm per day. Your usage is 2.5ppm/day. You can then adjust accordingly.

 

[Sonjaraz]

It really isn't too high, necessarily. With a CYA of 80 (the test is not linear, it cannot be interpreted between two values; you must round up), your target FC range is 6-11, so you're just barely off the edge of the range anyway. If it's steady at 11.5, I'd maybe turn it down just a hair so you're still targeting near the high end of the range, though I'm firmly part of #TeamRunHot. Move it down a few percentage points and retest to see where you land.

Thank you! I will try moving it down a tad and see where we land.

 

[Sonjaraz]

Is it steady at 11.5, or is it growing? The first step is to determine how much your pool loses per day. Do you have the pool math app? You plug in your 27,000 gallons, IC40 cell, 53%, and how many hours you run your pump. That tells you how much chlorine you create every day.

Example: You are creating 3ppm a day in chlorine, and your chlorine levels grow by .5ppm per day. Your usage is 2.5ppm/day. You can then adjust accordingly.

It's steady. I have the app but didn't realize I could check that! Thank you - will play around with the %

 

[Newdude]

This is a GREAT time to learn Sonjaraz. For the back half of the season, the UV demand / daily FC loss decreases ever so slightly each day as the days get shorter and the sun gets lower in the sky. When you miss an adjustment time, you make 'too much FC' and it's a GREAT way to screw up. If you miss an adjustment in the spring, with rising UV demand, you could be gifted a swamp if you don't catch it in time.

So have it in your head that for the rest of the season you'll likely be turning the system down each time. (Unless you turn it down too much, which you'll catch by testing regularly).