How to test for 12ppm FC CL with the TF TestKit?

lovingHDTV

LifeTime Supporter
May 25, 2007
529
Round Rock, TX
I just ordered the test kit for my pool. I have my water tested at the pool store and have 100ppm stabilizer.

Being in the Austin, TX area and my pool getting direct sun all day long I want to keep my CYA levels high. I prefer getting them down to 70-80ppm range. To do this I will stop using the tri-chlor pucks and will monitor till it drops to where I want it.

However, how do I test for the 12ppm FC CL that I need with a test kit that tests betwee 1-5ppm? I read something about using distilled water to change the testing range, but was hoping for a little more direction.

Is there some info out there somewhere?

thanks!
 

lovingHDTV

LifeTime Supporter
May 25, 2007
529
Round Rock, TX
Well I looked some more and it appears that I can use the OTO test for a daily test by using 2 parts distilled water to 1 part pool water and multiply by 3. This would give me a quick 5-15ppm test that I can do daily.

Is this correct?

thanks,
 

Buggsw

LifeTime Supporter
Apr 22, 2007
925
Arizona
Yes, that should get you close.

If you use 1:1 distilled water to pool water you multiply by 2.

If you use 2:1 distilled water to pool water you miltiply by 3.
 

The Mermaid Queen

TFP Expert
LifeTime Supporter
Mar 28, 2007
2,522
Northern KY
Your CYA level will not drop on its own. The sun does not affect it, and it does not evaporate. It will only get lowered through partially draining (or backwashing to waste) and refilling.
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
32,867
Sebring, Florida
That dilution method is not very accurate. It will be an indicator but I'd say +- 3-5ppm would be common.

Of course, with your new kit, you can do the FAS/DPD test and feel pretty comfortable down to .5ppm....very accurate up to 25ppm plus.

Perhaps you could do an FAS/DPD test and then an OTO dilution test right beside it to get a baseline color. Then you could do the OTO dilution daily "remembering" that baseline color in your mind.

I see your need for a quick test but you'll want to confirm your results every now and then with the FAS/DPD.
 

lovingHDTV

LifeTime Supporter
May 25, 2007
529
Round Rock, TX
What I wanted to do is a quick test daily or so, then an accurate one every week. Sounds like I will be able to do this.

I understand that CYA will not leave on its own, but with the amount of water that gets splashed out of my pool, and through backwashing I expect the CYA to go down over time. I won't be adding anymore anytime soon either.

thanks for all the help!

dave