Seal ring on Fluval 405

If there is any chance of tank water coming into contact with it I'd probably use vegetable oil, as any petrolium based oil could possibly effect your tank.
 
Checking the manual for my 404 it states you should use silicon lubricant.
Found this stuff silicone lubricant that should work. I mean its not the recommended fluval brand, but you know how that goes.

Quick edit here. Just have to say after 3 years I haven't lubricated the ring on my 404 and its doing fine. Now that you've mentioned it though I may order some soon.
 
I use to use a Fluval 304. Sometimes it would leak when I put it together. I found that if I got the seal wet before I put it together that it would normally stop the leak. I ended up getting an Eheim after a big mess one day and have been hooked ever since. No leaks, no noise, no headaches.
 
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