this may be a dumb question but here goes . i have a xp3 filter / pump whatever on my 55 gal tank . the pipe that allows the water to flow back into the tank should it be under the water or on top where the water returning falls into the tank ? i thought it was supose to fallin but i saw a pic and it looks like this guys is under the water . the reason for me aksing is because mine splashes water up onto the hood lid on the top cover of my tank and thin from there a bead runs down the front of my tank no major water leekig but none the less im tierd of cleaning the white line off the front of my tank everyday . also should i buy a tank heater ?