I have a fluval 205 that is leaking it pumps water but there is a pretty significant leak. I am filtering a 55 gallon. I am using a top fin 75 hob and i am looking to use the fluval with the topfin for adequate filtration. I was hoping u guys can lend me some help trying to figure out why the fluval is leaking. I am think about maybe the gasket is leaking.