Where to place outlet pipe

So in light of my recent questions regarding canister filters (as well as trial and error with them) i have decided to post my next question. I have noticed that when i put my outlet nozel under the water and bring it back up for the first 2-3 seconds the water does not appear to flow as quickly as what it does when it is out of the water (ie: above water level). Now my only explanation that i could come up with is that there would always be a slight pressure in front of the outlet nozel (if below water level) hence slowing the flow rate down, therefore i have left my outlet nozel above water level.

I also thought that if my explanation is possible, there would therefore be a slower flow rate, and hence more crap could get stuck in the pipe therefore more maintenance required, and hence more strain on the motor therefore more wear and tear?

Am i over-analyzing this theory to much or does my explanation with regards to where the outlet nozel is placed (above or below water level) make sense?

 

I think your last sentence says it Snail..... If any... the difference in flow-rate would be so insignificant that it should not be brought into the calculation..... The elevation of your canister (wether on the floor or an a stand would have a greater influence on your flow rate) where the water " Head" has to be considered..... (you may get a slightly better agitation when your outlet is above water due to the potential energy added due to the height of fall)

I merely have my outlet submerged as the constant sound of the flowing water would drive me mad whilst watching TV or trying to communicate.....