Yeah, I noticed that when I (shortly) had a glass thermometer. It made me nervous because they would NOT leave the damn thing alone, so I got one of the stick on side thermometers. A glass object breaking in the tank sounds like a nightmare!

But yes, the product was given to me after a water testing awhile back. It was actually pretty cheap, but probably not very useful except perhaps for medicine?
I use Seachem Prime and Stability(for water changes) and my tank health has been very good. The nitrates are higher than I'd prefer, but from what I understand planting should take care of that.

It really is amazing how most chain petshops know little/nothing about ACFs