Suction cups are worth pulling hair out, they either do not want to stay put as they are weak, or they lose function after being removed and applied a few times.
Why is every ornament "made" for aquariums a death trap for fish. The people who design them literally have no idea that inevitably a fish will get stuck in any number of the stupid small holes. I have kids, so they want "cool" decorations for the tank in their room, no matter how many times I tell them it is not a good idea (They are 7 and 4....so, that's why). It frustrate me to no end, I spend $12 plus dollars on a stupid cave only having to break it later to rescue a fish that tried go through the wrong hole or got stuck in a strange groove inside of it. Why can't artificial caves/ornaments be made more open on the inside with two nice large exits...oh, right, that's not "interesting"
The loud hum of the air pump...whisper quiet, my butt.
Finally, I have a canister filter that no matter how much i have tried to fix, it "belches" for 24 hours after I have done maintenance on it. I will be reading, the room quiet and all of a sudden, BLLABALLLARGH!!! Scares me every time! I have others by the same brand that DO NOT DO THIS. It is just the big beast and damn it sounds like one too.