I have a 150w aqueon pro that I've been happy with so far and it can go in straight up and down and not touch the bottom or stick out the top. They don't have the greatest reputation for lasting years but I wanted a 150 that would fit. There are others that will last longer and are better quality but I have had zero issues with it. I also got it essentially 40% off bc of the right timing in the year. Like I said though I also have a backup if it ever goes out but the backup is a preset and I keep it preset to 76 degrees. It hasn't came on except during a waterchange.Which do you use? That Ehiem is big and ugly lol