sump build questions

So im doing a inwall tank build putting a 150 gallon tank in the wall at one of my buildings now i want to make one of my old fish tanks into a sump, Iv been doing some reading on silicone to use and i saw a post that said the ge5000 was a good one but i saw on there that its mold and mildue resistant and i didnt know for sure if that was the correct silicone or not? has anyone used any type of silicone in a fish tank? any helpful ideas would be great thanks

 

Hey Guys thanks for the help, I have the ge1 silicone the part number is ge5000 from lowes im going to give it a try i got the walls up for the room that the tank is going to be in and i got the reef illumination light mounted and in the right spot and i also got the pvc overflow fitted and glued today, Im now looking for 2 50 gallon drums one for ro water and one for premixed water i know its going to be hard but im trying to find to tall and skinny 50 gallon drums so they dont take up the whole room, i have a little more mudding to do with the drywall then i can start sanding it and painting the drywall then hopefully i can add the substrate and liverock and water mid week. Its slowly getting there i will post some pics after its all done..