some great tips are in this thread
as for overfilling I still haven't found any solution, except that I stay close, often with a book.
I read a LOT and i just make myself comfortable near the tank with a book and keep 1 eye on the tank, 1 on the book.
"just checking the email and the forums" doesn't work!
internet is wayyyyy too addictive and I flooded my former apartment 2 times with hundreds of liters at refills when "just checking the mail"
I always recycle tankwater! room plants, the lawn, the rest of the garden: all do fine on fish-poo. i just elongate the hoses with pieces of eheim pipe until I can reach any part of the garden.
I also collect tankwater when washing out biofiltration sponges, bacterial medium and such.
cold water will shock-kill the bacteria, but rinsing them in surplus tankwater will not and you don't have to waste drinking water to do that.
careful with this one:
Lifting the lids on the tanks immediately lowers the temperature by 2 degrees F. Keeping the lids open overnight will keep the temperature at this lower temperature
many fish can jump and eel like fishes get out as well......
even clumsy looking things like callichthys are true escape artists and finding one's prize rarities covered in dust and still busy dying is no fun at all.....neither is being a slow waker and stepping barefooted on the dorsal spine of a dead catfish