epoxy or silicone

[edisondave]

I want to make some rock caves out of some slate I have. I was looking at epoxy at sears but am not sure which ones are safe to use in a fish tank. I dont know which would be better silicone or epoxy. If anyone has any suggestions as to which is better to use and could be more specific as to a name or brand to look for, or for any chemicals to look out for, I am thankful.

 

[HN1]

GE Silicone 1 should work and is aquarium safe.

 

[jsoong]

Make sure the silicone is totally free of any color & mildewcides. I have read on the GE website that the GE I is now re-reformulated with mildewcide, so it may no longer be aquarium safe. <I use a store brand - Rona - in Canada only - that has "aquarium safe" on the label.>

Silicone may not hold some rocks, and epoxy may be a better option. FAIK, once epoxy is completely cured, it is aquarium safe. <You need to use 2 part epoxy without any urethane or polyester resins, those marked "food grade" or "animal safe" should be OK.>