how are you meant to know when your goldfish are sleeping? they dont have eyelids so its quite hard to tell, my goldfish go down to the bottom of the tank at about 11 pm and they dont move till morning. is this them speeping? my granny has come to stay and she thinks they're ill!
do goldfish sleep or is it a myth?

Goldfish do sleep and when they are stationary at the bottom or kinda like "treading water" then that's the time the fish is sleeping.

Yep, d_golem is right. When goldies sleep they just sort of float around the tank. If this starts at 11 PM and lasts until morning time, then I would be willing to bet its just sleepy time! How do they act during the day? Normally?

yeah, they act noramal during the day apart from the oranda, it keeps looking like its dead! its floats up and down and stays upside down at the top 4 hours on end (no its not dead yet)!!!!!!!!!!!!!!!!!!

An upside down goldfish is definitely not good. maybe SBD? maybe fast ur oranda (maybe even all ur fish) for 3 days and feed nothing but lightly-cooked deshelled peas for 3 days.

my other goldfish are fine, what is SBD? my oranda sort of floats at the top in the same position and doesnt move. it's really sick at the moment, doies this he'll die?