Aquarium Sealants

Question
I am wanting to add a glass piece to the top of my used 75
gallon tank that I just bought like there is on my oceanic
55 gallon that i have. Across the middle of the top of the
tank where the separator piece is, my 55 gallon has a glass
piece that is about 6 inches across. You can lay the top on
this instead of the thin plastic separator. I want to add
one of these and what to know what time of sealant would be
safe to use as an adhesive to hold the glass piece in
place.

Answer
Hi Debbie. The only sealant that I would recommend for use in a saltwater tank is a regular silicone made especially for use in an aquarium.The All Glass Aquarium company makes one and you can usually purchase it in any aquarium supply store. Don't use any that you may be able to pick up at your local home store. While I am sure they sell  that would be perfectly safe you don't want to take any chances. Some sealants can leach out especially under the corrosiveness of saltwater and lower your pH substantially. Any time you need to silicone anything to a tank you will want to wait at least 48 hours for the sealant to dry before adding water to your tank. Also always work in a well ventilated area. Those fumes can really go to your head!