Quote Originally Posted by JustAlex4tw View Post
It's definitely and in-ground pool. I'm not certain if it's Concrete or Gunite - How can I tell?
Gunite is one form of concrete.

It's not too critical, if you follow the dose => test => dose again approach I advocate. If you try to use the pool store, or even the PoolCalculator.com approach of 'dose all at once', it becomes critical.

Overdosing with chlorine is almost never a problem. Don't try to single-shot doses of anything else, and there won't be a problem.