Fluval 205.

[molotov]

I have a fluval 105 and I found that the O-ring can sit in a position that looks like it fits but is the wrong position. Instead of placing the O-ring on the top portion try placing it on the canister portion and seating the top.

Also I've read that Vasaline is a petroleum based product and was advised not to use it. I'm not saying the guy who recommended it is wrong. I just don't know what to believe as far as vasaline goes. I was personally going to lube all my o-rings with it but was talked out of it.