We used to have a chemical company take care of our pool?

Question:Sometimes there would be this white powder stuff sitting by the steps in the shallow end of the pool....I think they said it was a conditioner. Any ideas what this is or could've been?

Answers:
There are various chemicals used in pools that are white powders.

I would venture it was one of the following
Baking Soda
Chlorine
Cyanuric acid
sodium bisulfate
soda ash
alum

These are the things one would "condition" the pool with.