I've got 5 tubs set up with 11" flexwatt heat tape, each one is 1ft in length.

the instructions say that each foot uses 20 watts , but wanted to add some more stuff on another power bar for my display tank using the same outlet. I'd like to work out how much current its going to be drawing so I don't keep tripping the breaker, or cause a fire .

In the display tank I was planning to put in a fan , light, and a water pump for a waterfall.
I want to have two power bars on one outlet , and its a 15A breaker.

anyone know how to work this out so I know how much power its going to be using so its still safe?