pool math app recommendations vs pool store recommendations

[Angelnorgaard]

Here are today’s readings on my freshly filled pool. Pool math app says to add 5 lbs of dry acid and pool store says add 2lbs and to not use muriatic acid as it will damage the vinyl liner, how much to add ?
Also
Installing bigger sand pump tomorrow as the one bought with the pool isn’t big enough. Do I start adding chemicals knowing that we’re going to have to drain it down to change out hoses to fit me pump?

 

[mknauss]

Welcome to the forum!
More importantly, you need to add chlorine! And CYA.
Muriatic acid is superior to dry acid. Dry acid is sodium bisulfate. As you add it, the the sulfates build up in your pool water.
If you have a heater or SWCG, that is not good. Can you fill out your signature?
Your Poolmath log shows 17000 gallons. So to lower pH to 7.4 with a TA of 240, add 64 oz of 31.45% muriatic acid. Or 5 lbs of dry acid.
I suggest you read ABC's of Pool Water Chemistry and consider reviewing the entire Pool School eBook.

 

[mknauss]

I would at least add chlorine tonight, 3 ppm FC worth.

The pH can stay at 8 until you do your fixes.

 

[Divin Dave]

Hi Angel,
If you pour muratic acid slowly into the pool, in front of a return, it will not damage your vinyl liner.
If it did, there would be 100s of people here at TFP, telling you not to use MA in a vinyl pool.

 

[YippeeSkippy]

Immediately after pouring MA into my pool, I brush the area entirely just to avoid any potential problems.

Maddie