your supposed to use silicone 1 because it dosnt have the anti mildew and stuff but i can never find it. the walmart aquarium sealant isnt too expensive and it works fine.
Since we are on the topic, I was wondering something. I am planning on building a slate cave for a tank and was thinking I could save some money and go to Home Depot for the silicone. Will they have the right stuff for me? Would it be cheaper than the All-glass aquarium stuff they have at Big Al's? I will be going to both stores tomorrow but Big Al's will be first so I would like to know before going. Thanks guys.
Home Depot and most hardware stores will carry the silicone. It does take a little reading to get "just silcone" but worth it. For building a slate cave or any heavy rock work I would suggest epoxy instead of silicon. The silicone tends to loose its bonds with rock surfaces when submerged over time. Many epoxy cure inert and should be non-toxic then.