AG weekender owner new to TFP, CYA 100, advice please thanks!

[Poolweekender]

Hello all,
Many thanks for this forum.
Last year I had recalcitrant pink algae (bacteria), and after reading TFP school over the winter, I guessed I had high CYA since I've used pucks from the pool place for 25 years. And I was right

Pool was opened May 3 and pool center added 5 gallons chlorine (I think ).
On May 4, using TF-100 I measured:

Water very cloudy
FC 1.5
CC 1
pH 6.8
CYA ~ 80
(no other measurements sorry).
​

On May 5, I took water to pool center (for the last time!), and they read the same as above except a CYA of 100 (of course they had no idea of the relationship between CYA and how much FC is needed).
They had me add another 5 gallons of chlorine to pool, which I did on May 5.

TODAY MAY 6:

Water moderately cloudy (getting better)
FC 33
CC 0.5
ph 7.2
TA 70-80
CH 125
CYA - I didn't repeat.​

So with a CYA of ~ 100, I read from the chart that my Shock FC should be 39, so I'm not far away .
I can slowly empty and replace the pool water, but I have a well...I can only do a little each week...so getting rid of the CYA will be a long-term project.

Please, am I off to a good start for the moment? The pool is getting clearer each day. I cannot do any testing from Monday to Thursday as I will not be at the house.

The big, but longer-term question, please, if it is appropriate to approach this now --
I am at the house only on weekends and I really don't want to invest in a SWG at the moment.
After I get the pool in initial good shape....
1 -- Can I shock with enough liquid chlorine each Sunday to hold the pool for 4-5 days (from what I've read this is not possible,, but why?...is it because my FC would need to be too high on Sunday and there is a negative in that (maybe bleaching?))
2 -- With a CYA of 100, I certainly will NOT continue using any dichlor/trichlor (which the pool company has giving me for years). I could use lithium but it is too expensive. Could I use calcium (hypochorite?) since my CH is relatively low?

Any advice appreciated, thank you very much!!

Justin, weekend pool owner

 

[Texas Splash]

Hello Justin and welcome to TFP! About your concerns:

Can I shock with enough liquid chlorine each Sunday to hold the pool for 4-5 days

It will be close. Certainly not ideal, but once you pass your current SLAM and know the water is algae-free, depending on heat and sunlight, the FC might be close to the minimum.

Could I use calcium (hypochlorite?) since my CH is relatively low?

Yes, although bleach (I believe) is usually a bit cheaper, easier, and more accurate to dose to higher levels.

You have the concept down now that you have a TF-100. Now it's just a matter of time management. Each pool is different, so watch your testing and adjust accordingly. Keep the pH in the mid-7s - never lower that 7.2 or higher than 7.8 if you can help it. Of course pass your current SLAM to remove algae and cloudiness, then do your best to maintain the FC above the minimum while you're away. Later you can post your own TA and CH and we can help you with those as well if you need help. Enjoy the weekend.

 

[Poolweekender]

Hi again, I'm new to BBB and still trying to figure things out.
I assume I can continue to post here for now...but if not, please let me know.
And thank you very much TEXAS SPLASH!

OPENED POOL MAY 3
YESTERDAY MAY 6:

Water moderately cloudy (getting better)
FC 33
CC 0.5
ph 7.2
TA 70-80
CH 125
CYA - I didn't repeat.
​

TODAY MAY 7

Water mildly cloudy (getting better, also I just changed DE so may be more efficient now).
FC 23.5
CC 0.5
ph 7.0
TA 80
CH 125
CYA 40 (doesn't make sense, but I repeated x 2...last readings a few days ago were 80 (mine) and 100 (pool store)).​

So I'm thinking:
1 - FC is high enough if CYA is 40 (5-7) or 100 (11-13), so I'm ok for now -- I have to get a reliable level of CYA.
2 - I want to raise ph from 7 to 7.4. Pool math says to add 35 oz of soda ash, I will add 20 oz to start and check the pH.

Uneducated question:
FC is down from 33 to 23.5 in one day -- that is too much, correct? Does that mean I mean have algae even though I can't see any? I have only a few leaves and a bit of dirt in the pool after cleaning it 2 days ago.

Any help is appreciated, thank you very much!

Justin, weekend pool owner

 

[Texas Splash]

CYA 40 (doesn't make sense, but I repeated x 2...last readings a few days ago were 80 (mine) and 100 (pool store)).

Hummm. That is very odd. Let's re-cap a couple very important things for you:
- The CYA test is the cornerstone of water clarity because it tells you what your FC should be. There's no way your CYA dropped from close to 100 to about 40. That would require changing-out 50% of your water. There must have been some testing errors. (see below)
- Remember you haven't completed the SLAM yet to ensure the algae is all killed. The pool is still cloudy, so algae is still present. You must pass all 3 SLAM criteria before letting the FC level drop. To answer your question - "yes", I suspect a big reason you lost so much FC is because of the algae still present. Remember ... "maintain" that (correct) SLAM FC level.
- I would not increase the pH yet because you still are working the SLAM.

Definitely be sure about that CYA. Here's my at-home testing method:

Proper lighting is critical for the CYA test, so you want to test for CYA outside on a bright sunny day. Taylor recommends standing outside with your back to the sun and the view tube in the shade of your body. Use the mixing bottle to combine/gently mix the required amounts of pool water and R-0013 reagent, let sit for 30 seconds, then gently mix again. Then, while holding the skinny tube with the black dot at waist level, begin squirting the mixed solution into the skinny tube. Watch the black dot until it completely disappears. Once it disappears, record the CYA reading. After the first test, you can pour the mixed solution from the skinny view tube back to the mixing bottle, shake, and do the same test a second, third, or fourth time to instill consistency in your technique, become more comfortable with the testing, and validate the CYA reading.

Hopefully that will help.