Dry Acid vs Muriatic Acid Question for those with a Vinyl Liner

[Jsf721]

So I have been using Dry Acid in my Vinyl Lined Chlorine Pool. I learned on this site that Dry Acid adds other "Suff" that is not good for the pool. So last night I went to Ace Hardware to get 4 gallons of Muriatic Acid and stock up for when I finish the Dry Acid.

The shelf for the Muriatic Acid was empty and I asked for help. They were out, but the guy said if you have a Vinyl liner never use the Muriatic Acid bc it heavier than water and sinks and damages the liner.

Did I not understand something? Or does this guy not know what he is talking about?

If this guy was wrong at ACE, what is the correct method for adding Muriatic Acid to the Pool so the liner is not damaged ?

 

[mknauss]

Add muriatic acid at the pool return with the pump running in a pencil sized stream.

If necessary, brush the area after adding.

 

[Jsf721]

Add muriatic acid at the pool return with the pump running in a pencil sized stream.

If necessary, brush the area after adding.

Thanks very much.