Koralia 4 making loud noises and vibrating?
 

I have two koralia 4 fans each make loud vibrating noises one was so bad i pulled it out of tank. How do you fix this? They are expensive in the store and id hate to have to replace them!

They sometimes go quite but not for long

Try cleaning them out, could be calcium deposits.

Ill give it a try, getting annoyed now mabey will replace propeller..

I had to replace the propellers on both my Koralia 4 and haven't had any problems since. Ordered the propellers at Aquarium.com - relatively cheap. Good luck!