Why Add Shock if FC is high and CC is low?

[Jamie Languedoc]

With temps in the mid 80's this week we decided to open the pool early this year so we took the cover off last night and hooked everything up. I tested the water and found my TC was still high from closing, PH was low, ALK was a little low and CYA was good. I took a sample to the pool store to have them test for salt and borates because I'm out of testing supplies for those and they told me to add 3lbs of shock along with 5lbs alk up and 25lbs calcium hardness. I will add baking soda to get the PH and ALK up, but I'm confused as to why they are telling me to add shock when my FC is still so high right now. Any ideas?

FC 6.34
TC 6.4
CC 0.06
pH 6.9
TA 48
Ca 49
CYA 46
Phosphates 300
Salt 3967
(They were out of Borate testing supplies too.)

 

[PoolStored]

With temps in the mid 80's this week we decided to open the pool early this year so we took the cover off last night and hooked everything up. I tested the water and found my TC was still high from closing, PH was low, ALK was a little low and CYA was good. I took a sample to the pool store to have them test for salt and borates because I'm out of testing supplies for those and they told me to add 3lbs of shock along with 5lbs alk up and 25lbs calcium hardness. I will add baking soda to get the PH and ALK up, but I'm confused as to why they are telling me to add shock when my FC is still so high right now. Any ideas?

FC 6.34
TC 6.4
CC 0.06
pH 6.9
Alk 48
Ca 49
CYA 46
Phosphates 300
Salt 3967
(They were out of Borate testing supplies too.)

I don't know why you would shock either. To rule out the need, do this -->Overnight Chlorine Loss Test

Why are you using the pool store to test your water when you have a gold standard test kit?

I would test with your test kit, THEN add what is needed using those numbers.

I don't know why you would take advice from the pool store.

Sincerely,
PoolStored.

 

[YippeeSkippy]

Please do NOT do anything the pool store has said to do. Please reorder test reagents: www.tftestkits.net
Vinyl pools do NOT need Calcium. Just sales scare by pool store.
If your pool still has FC, you don't need "shock".... same sales gimmick as above.
DO NOT add baking soda until you perform a test with the TF-100.... their test results are entirely unreliable. How do you get a result of "46" for a TA test?? Beats me.
If you believe the pH result you can run a fountain or some other splashing method and raise the pH without chemicals. Here's how I do it-

IMG_0481 copy.JPG

• YippeeSkippy
• Jul 3, 2019

Maddie

 

[YippeeSkippy]

FYI- *if* you were trying to raise your TA & pH, you could use Washing Soda, not Baking Soda.

 

[Jamie Languedoc]

Thanks everyone. I only really went to them for testing so I could see if I needed to add salt (and how much, because I'm out of salt testing supplies) because I already knew my other levels from my own test kit. I do need to raise both pH and TA, but I only have baking soda, not washing soda at the moment. I normally just aim my return up to generate some air bubbles/splashing to raise my pH. I don't care at all about calcium since I know that makes no difference with my pool. I just couldn't, for the life of me, understand WHY they said to add shock. I wasn't planning on it anyway, but I wanted to see if anyone else had a clue why they would recommend it. Crazy. Of course they asked me before I left if I needed to purchase any of the chemicals and I just simply said I already had everything I needed. I generally don't tell them I NEVER use their Crud and always use the bleach, baking soda, washing soda, and those sorts of things. It just saves time because I don't want to hear their nonsense when they want to argue that their products are better. I've got salt and borate testing supplies on order now so I don't have to worry about them again. I really felt sorry for the poor guy the next counter over being sold over $100 worth of product. I wanted to catch up to him when I got finished and tell him there's a much better way, but he was already gone when my samples was finished.

 

[PoolStored]

so I could see if I needed to add salt (and how much, because I'm out of salt testing supplies)

I would not trust their salt testing capabilities if you paid me.

If it is inaccurate (low) and you added more salt than you really needed based on faulty testing, then you wasted $$ on salt and are into draining the pool!

 

[an1vrsy]

I wanted to see if anyone else had a clue why they would recommend it. Crazy. Of course they asked me before I left if I needed to purchase any of the chemicals

You answered your own question without realizing it. Their business model is to sell you stuff, expensive stuff.