Source: US Census. The median household income in the US is $50,502. This is some extremely useful data given that it is exploring over 114 million US households. If you want to know how most Americans are living this is a good figure to base your assumptions.
The myth that you have to wait 30 minutes or even an hour until you can swim after eating has been conventional wisdom for some time. The simple fact is, however, that swimming on a full stomach does not significantly impact your ability to swim.
I was wondering how long should I wait before I let my family go swimming after adding a pH minus or pool acid. I would suggest a good 2 hour wait before you go swimming again. This will allow the muriatic acid to do it's job. Your swimming pool might increase in pH naturally as more people swim in it.