I'm currently constructing a 29 gallon vivarium with a waterfall as the centerpiece. How i have it set up is so the water will fall down a large piece of wood. Now the piece of wood is nice and cleaned and has been weathered for some years.

My friend is telling me that i need to cover the wood that is going to be in contact with the water in epoxy...is this true?

he says if not it will rot. But if my wood has already been weathered, will that make a difference?

and also instead of epoxy would i be able to use clear silicone instead?