Anyone has any idea how much wattage the Daeil 1/4hp chiller is using?

I just wanna calculate how much I am actually paying to chill the tank.

It kicks in every 1.5hrs, and lasted 15minutes to chill down the temperature by 1C. I calculated based on 4oo watts and it will roughly cost me from $10 - $15 per month.

By-the-way, I am running it using a eheim1250 pump. Any idea if it's efficiency will improve if a higher flowrate pump is used?