Question about pool chemicals and opening our pool

Aug 17, 2018
20
Milwaukee, Wi
Pool owner for many years. 25K gallon, in ground, gunite.

Just opened the pool today after a harsh Wisconsin winter. We had our first bout of algae EVER in August 2018 that took a lot of work and time to clear up - just in time to close the pool for winter. We have the TFP test kit and we used the SLAM process to clear everything up prior to closing. Using the TFP test kit was NEW to me so I am not super-familiar with all of the tests and all of the acronyms used on this website.

Right now the pool is open, filter running, etc. Typically (in past years) at this point I vacuum the pool to "waste" and clear up the worms and junk on the bottom of the pool. I also add algaecide to specifications on the bottle for the size of our pool and about 2 gallons of shock. I did NOT do that this year because I want to do it right.

Do I test first (what tests exactly) with the kit? Do I begin to add pool shock and/or algaecide? Do I do the SLAM procedure now? Do I vacuum now (to waste?) or do I wait till the chemicals are added?

Right now the pool water is cloudy and dirty, but I can see the bottom in the 3.5-4 foot shallow end. I can see parts of the bottom in the deep (8 to 8.5 foot) end.

THANKS for your help. I want to open the pool correctly and maintain it correctly from now on. I can post test results - just let me know which numbers would be helpful. I am somewhat familiar with using POOL MATH and I have read POOL SCHOOL and some posts on the TFP forum, but as I stated earlier some of the acronyms are foreign to me.

Thanks again.
 
Aug 17, 2018
20
Milwaukee, Wi
The system has been running for a few hours. I ran all of the tests listed on the WEEKLY TEST side of the TFP instruction card that came with my test kit.

Here are the results
  • CYA = 20
  • No Chlorine
  • TA = 100
  • Calcium = 200

Thanks for your help.
 
Aug 17, 2018
20
Milwaukee, Wi
OK. I flipped the card over and did the DAILY TEST for ph and it is 7.8.

I went to the pool math link and added my pool size, CYA number, ph, and FC (0). I wasn't sure what my goals should be for each area on this calculator, so I left the defaults - except for FC which you said I should aim for "3." The default setting for the right column of FC said "6 weight %" I wasn't sure what that was. My chlorine says 12.5% sodium hypochlorite so I changed the 6% to 12.5% (and the calculator changed the word "weight" to "trade" when I changed the 5). Is this correct?

I am not familiar with the sock method for adding CYA. My level was 20 and on the pool math calculator I put in target of 40, and the result on the right says:
"Add 67 oz by weight or 70 oz by volume of stabilizer
or add 173 oz of liquid stabilizer."
Is this what you mean by add 10 ppm of CYA? Is that the same as (for example) 67 oz by weight? And is the 40 CYA target an accurate goal? Do I place that in a sock in the skimmer basket?

Can I vacuum (to waste?) and brush the pool after adding the chemicals? Can I add the shock and stabilizer (CYA) at the same time?

One last thing. On the pool math calculator webpage on the left hand column, for every area it says "Goal: Not Setup." I have my TARGET numbers in but what does Goal not set up mean?

Sorry for all the questions, but I want to be sure I am doing this correctly.

Thank you. :)
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
23,517
Laughlin, NV
7.8 is fine for now. If you need to SLAM you will wan to lower that.
Be sure you have selected TroubleFreePool as Goal levels.

I suggested only targeting 30 ppm CYA for now as you may need to SLAM.
You change the % chlorine to what you are using.

Vac to waste first.
Add the CYA by using what we call the sock method. Get an old sock (no holes) and put the measured amount of CYA you need. Tie the sock closed and either suspend it in front of a return (hang it from your brush pole works with something weighted on the deck) OR if it still allows flow thru the skimmer, place the sock in the skimmer. Every 15/20 minutes give the sock a squeeze to speed up the process. Please DO NOT follow the directions on the container of CYA to just pour it into the skimmer and don't just toss the sock in the pool as the CYA is acidic and can bleach/stain pool finishes.
 
Aug 17, 2018
20
Milwaukee, Wi
Great. Thanks to mknauss and Mr Bruce. I appreciate your help. I am off to do everything you suggested. I will post back later tonight or tomorrow with the Overnight Chlorine Loss results.

There is some algae (?) visible on the steps. Actually, not sure what it is - but it is loose green stuff. I was able to vacuum most of it to waste. The water is a little greenish. Hard to tell what is on the bottom but I did vacuum a lot of leaves into the skimmer basket. Hopefully I can clear this up without SLAM. Thanks again.
 
Aug 17, 2018
20
Milwaukee, Wi
It was suggested that I "Plan to do a Overnight Chlorine Loss Test tonight or tomorrow night." I will do that test tonight and tomorrow morning.

For today - should I do the CYA test and the FC, TA, Calcium, ph tests, too?

The CYA that I added via the sock method is not even half gone. I squeezed the sock every 20-30 minutes last night till bedtime and again this morning.

Thank you!
 

Oly

Gold Supporter
Jun 28, 2017
1,221
Fresno, CA
Wait a couple of days to test CYA after completely dissolving the addition. FC, CC and pH are the important tests now.
 
Aug 17, 2018
20
Milwaukee, Wi
Thanks.

FC = 2.5
CC = .5
pH = 7.8

I left my Target FC at 3 (as suggested above yesterday by mknauss). Is that a good goal? Based on being at 2.5 and target of 3 FC, I added the suggested amount of 13 oz of 12.5% shock.

I am not sure where the CC number goes on the pool math calculator.

I am thinking to leave the pH as is for now? (Also suggested above.)

Thank you!
 

Oly

Gold Supporter
Jun 28, 2017
1,221
Fresno, CA
CC is a quick diagnostic test and can indicate pool water problems, a number of less than 1 is not a concern.
Yes keep your FC at three or slightly above then follow through by completing the Overnight Chlorine Loss Test
Be sure to follow the instructions exactly. I would suggest using the 25ml sample protocol rather than the 10ml for better resolution at your FC level.
Once you have the results post them here and you can begin to develop a plan.
 
Aug 17, 2018
20
Milwaukee, Wi
Things have been going OK with my numbers and the clarity of the water.

I do have a question. How do you know when to shock your pool? Do you shock on a schedule OR just after a situation such as heavy rain, heavy pool use, water level increases, any other situation? Or do you do both - shock once a week AND after a situation? How much shock do you add for a 25K gallon gunite pool?

And, lastly, on the chart on TFP at this link there is a column for Shock Level. Chlorine / CYA Chart - Trouble Free Pool

How do you measure Shock Level - or is that column just saying "Shock when your FC gets to this level?"

Thank you!
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
23,517
Laughlin, NV
You follow the SLAM Process process when your pool testing indicates it. Your CC is 1 or above, your FC is dropping more than it is supposed to be, you have algae, cloudy water, etc. We never 'shock' a pool. Shock is a noun, for a product, not a verb.
 
Aug 17, 2018
20
Milwaukee, Wi
Thanks. So if I understand what you are saying, just keep my FC where it is supposed to be and only use the SLAM process if testing indicates it with the examples you have listed above ("Your CC is 1 or above, your FC is dropping more than it is supposed to be, you have algae, cloudy water, etc.").

On the chart on TFP at this link there is a column for Shock Level. Chlorine / CYA Chart - Trouble Free Pool What does it mean when it says in the fourth column of the chart (for example) "Shock Level 12"?

Thanks again.