Leakage problem with Ehiem Professionel 2

[celticfish]

two more cents from little old men!

the "grease" is silicon base.
it coats the rubber and lengthens the lifespan of an O-ring or rubber seal.
for diving they recommend changing it every year (mind you lives are involved).
but i reckon an O-ring should last at least three years if you grease it well.
it helps the rubber from drying out and hence maintain its elasticity.

BFG,
i'd like to suggest you grease your O-ring before storage.
you can put them in a zip lock bag after greasing.

[stephen chung]

Agree with celtifish. You should grease your o ring or rubber seal b4 using it or you want to store the unit away.

It is important that you use silicone grease.