For the Hell of it, here is my systems.

[justinl]

whooo weee nice tank! I have to agree with what was said above, the placement of it all is very well done.

marie: Ive heard of this before and it's not anything really uncommon (nothing to worry about at any rate). I think it's more than anything the fish having a bit of fun. I think there was even a video of this behaviour on youtube... or some forum maybe?