Agreed, milky white bacterial blooms are extremely common in a new tank and are nothing to worry about, as they go away relatively quickly.
They are caused mostly by a sudden temporary overpopulation of "heterotrophic" bacteria (not the bacteria we are trying to grow but different, faster growing bacteria that break down the waste in the tank into ammonia) it is believed.
An external cannister shouldn't be making enough noise to bother you. You may have the spray bar output adjusted to high at the water surface. You should be able to slide it down relative to the surface such that it creates a lot of movement but very little noise. This will still promote a lot of the desired gaseous exchange. Another thing to check, if you haven't already, is whether any air bubbles from the media are trapped up at the pump head. Whenever you re-prime and start an external cannister it is good to lift the entire cannister and rotate the head at slight angles, giving it a shaking motion as you do this. If there is any air, you should hear it as it hits the impeller and then hear it shoot out of the spraybar. Be careful that you don't pull off any hoses when you do this.
Also be aware that you can try different water stream positions of your spraybar outlets to change the flow pattern in the aquarium. An external running on a 17g could possibly wind up blowing the fish around rather swiftly and you may want to watch them swim rather than be blown around. Sometimes pointing the output holes back at the glass will work.
~~waterdrop~~