Yes you can the muriati acid is used to get the pools pH to between 7.2 and 7.6 then you can add the pool shock as per the instructions.
You can't! Muriatic acid (~32% HCL) will not add any free chlorine to the pool and will not function as a oxidizer (Shock).
None until you add it.
Add muriatic or hydrochloric acid.
Yes, you can use muriatic acid to control pH in a pebbletec pool. Added correctly (spread around the pool with circulation equipment operating) muriatic acid will not harm the pool. As a matter of fact muriatic or hydrachloric is the best thing to use but I suggest you dilute it 4 parts water 1 part acid for safety to you and your equipment
The original question was the better of the two questions. Is it ok to add muriatic acid while the pool is in use? When is the best time to add muriatic acid? You should either wait until no one is going to use the pool for a while. It is not a good idea to add chemicals to the pool while someone is in it. Best to add chem. first thing in a.m. before use - then let circulation distribute those chem. k
use either muriatic acid or dry acid (sodium bisulfate)
Hydrochloric acid is most commonly known as muriatic acid and is used to lower pH in pools
Add acid, Muriatic acid works best but Dry Acid is also used.
Usually you would add muriatic acid to adjust the pools acid level.
Approx. 5 to 15 minutes. Or enough time for the circulation system to disperse the chlorine. Or you could add it to the opposite side of the pool. Remember not to add the acid to closely to the skimmer or main drain.
Add potash. See your pool shop with a sample of your water and the size of your pool and he will give you what your pool requires.
You can add dry acid to your pool when your pH is above 7.8