Using pure O2 in a fish tank

Question
QUESTION: Hi, I work for an oxygen company and have access to bottled pure oxygen, I am thinking about running a tube into my tank, but I dont want to if its going to harm my fish??
Hope you can help

Rory

ANSWER: Hello Rory,

Why would you want to do that? its a waste of pure o2.

---------- FOLLOW-UP ----------

QUESTION: Thats for me to worry about, I just need to know if it will harm my fish??

Answer
Hello again,

If it where me I would not do that because it can kill the fish if they get to much of it. What size tank do you have and what kind of fish, also where did you purchase them because some stores are more prone to disease from how they ship them.

Thanks,
Michael M.