Answer: A. 1 hour
Explanation:
It is generally safe to swim just 1 hour after adding muriatic acid to a swimming pool to adjust the pH levels, however, you should always check the pH levels before swimming, especially after adding something to the water. Muriatic acid can create spots of acid in the water that could irritate your skin. To prevent this, leave the pump running for at least 30 to 60 minutes or brush the pool floor for this time.
