Free chlorine - morning vs afternoon?

poolFreshwater

New member
Sep 6, 2021
4
Ontario, Canada
Pool Size
16200
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Good day,

I'm a total newbie - just got started with a brand new 16,200 gallons pool last Friday with city water added. I did try to read through the materials... not enough reading and practice though.

What have I done:
  1. added the salt to the fairly reasonable level 3450 (as per the reading in the Pentair Intellichlor device) and started the SWG after 24 hours (60% setting)... it has been running for 36 hrs now
  2. added the liquid chlorine 1.5 days ago (~7L).
  3. tested with test strip this morning at 9AM (~36 hours after adding liquid chlorine), the Free Chlorine reading is medium/high on the test strip
  4. tested with test strip again at 1:30PM, the Free Chlorine reading is very low
  5. water tested at the pool at 2:30PM: Free Chlorine is very low at 0.19ppm, CYA: 3ppm, Calcium Hardness: 32ppm, Alkalinity: 35ppm, pH: 7.8
Questions:
  1. Is it normal for Free Chlorine to drop significantly during the day at in the afternoon in comparison to the morning?
  2. Can I swim with this low Free Chlorine in the afternoon (aka. - I have algea based on the testing result attached)?
Next steps - in order recommended by the pool company:
  1. Bring up Alkalinity with 7.9kg of Alka-Plus-Pool: 3 dosages at 2.6 kg each with 1 hour in between
  2. Wait 1 hr
  3. Add liquid chlorine: 55 oz (10.5% liquid chlorine). Do I need to continuously shock the pool?
  4. Wait 1 hr
  5. Add calcium hardness: 15.4kg - 3 dosages at 2.6kg with 1 hour in between
  6. Wait 1hr
  7. Add Cyanuric Acid: 2.8kg in a nylon sock and put in the skimmer
Please let me know if my steps need adjustment. I plan to follow this tonight.

I am going to buy the Taylor testing kit tonight - hopefully it doesn't take long to ship here.

Thank you!
 

Attachments

  • 2021-09-10 - Water Testing.jpg
    2021-09-10 - Water Testing.jpg
    448.6 KB · Views: 5

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2014
33,813
Texas, San Antonio/Marion, South-Central Area
Pool Size
17888
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
CircuPool RJ-45 Plus
Welcome to TFP! :wave: The pool store guidance is not good. Ironically enough they are often wrong. Here's a priority get-well list:
1. Get a TF-100 (from states) or Taylor K-2006C. We'll follow up with other options north of the border. Test strips are junk.
2. If you never added stabilizer, you need it ASAP. Your season will end soon, so perhaps a CYA of 40 - 50 will work for now. Add stabilizer via the sock method. See below.
3. Keep the FC at about 3 - 5 ppm. Use liquid chlorine or regular bleach if needed to help your SWG until you get it adjusted properly.
4. Focus on the pH being between 7.2 - 7.8. Don't get all wrapped up in the other things right now. After you add stabilizer, FC & pH are your priorities.
5. Don't buy pool over priced pool chemicals. Muriatic acid from the hardware store to lower pH when it gets too high and liquid chlorine for FC when your SWG needs help. Regular baking soda is all you need to raise TA, but be sure to confirm with your own testing first.

The test kit is a must. We'll help you.

 
  • Like
Reactions: Mdragger88

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2014
33,813
Texas, San Antonio/Marion, South-Central Area
Pool Size
17888
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
CircuPool RJ-45 Plus
For the CYA ..

Adding CYA:
To increase CYA via granular stabilizer, place the required amount as calculated by the Poolmath calculator into a white sock and place in the poolside skimmer basket. For those concerned about suction flow to the pump, suspending the sock near a return jet or from a floating device will also suffice. Best never to allow undissolved granules to rest directly against the pool surface. Squeeze the sock periodically to help it dissipate. Once dissolved, consider your CYA adjusted to that programmed (target) level. CYA test readings should show a rise in 24-48 hours, however some pools may experience a longer delay to fully register. Best to confirm final CYA in about 5-7 days before adding any more stabilizer/conditioner.
 

poolFreshwater

New member
Sep 6, 2021
4
Ontario, Canada
Pool Size
16200
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Thank you so much for your detail instruction!
I have added more chlorine last night and going to buy a sock to add CYA tomorrow.
I searched on the test kit and found this one. Not sure if this is the 2006c or only the 2006 version? It has the word comp in it but not specifying 2006”c”

Thanks!

 

Weasel2017

Bronze Supporter
May 18, 2021
63
Canada
Pool Size
10700
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Jandy Aquapure 1400
Taylor K-2006 Complete Chlorine Test - Pool Supply Haus Ottawa Ontario Canada This is where I got mine, quick shipping and great service. Only the K-2006 but they will sell you any extra reagents you need. This time of year the K-2006 will be adequate and you can re-fill with fresh reagents next season.
Also, they don't show the K-1766 salt kit or the speed stir on the retail site but if you inquire they will sell those to you as well through their commercial division on the same order. Strongly suggest the speed stir!!
 

Enjoying this content?

Support TFP with a donation.

Give Support

Weasel2017

Bronze Supporter
May 18, 2021
63
Canada
Pool Size
10700
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Jandy Aquapure 1400
Thank you! Unfortunately I live in Canada so that site doesn’t work for me. I will do a search for the c version then.

In addition, does a fabric sock work for holding the CYA agent (e.g link is below)?

If you are talking about adding Stabilizer, just use a regular sock/stocking suspended in front of one of your returns. Tie it to the end of a broom, just keep it away from your liner and make sure you weigh it down so it doesn't fall in. Give it a squeeze every once in awhile to speed it up.
 
Thread Status
Hello , This is an inactive thread. Any new postings here are unlikely to be seen or responded to by other members. You will get much more visibility by Starting A New Thread