Wont anything you add to the tank create water movement? If its sucking up water its got to come out one way or another and when it does its obviously going to great some type of current. I am assuming you have little axolotls since you posted this in the Axolotl tank set up. Hagen Elite Underwater Mini Filter is for aquariums up to 3-gallon, axolotls require 10 gallons each so your better off buy air tubing, pump, and a small sponge filter ( all will cost $30 or less). It will create a small current but it wont effect the axolotls, i put one in the tank i raise my axolotls in from when they were eggs, it never seemed to bother them.