re sealing bottom panel

[pastout]

so i know there are some people on here who have done this and im looking for a litle guidance. a few days ago i picked up a 40 gallon tank 36x18x16 with a bottom panel thats silicone seal has let go. i have no intention to use this for fish it is actualy for dart frogs. so i olny need it to hold 3- 4 inchs of water max. so i was planning on removing all the silicone from the bottom panel and re siliconing it to the sides. what type of silicone should i use? can i get away with the tube that all glass makes for the bottom panel?the one you put in a caulking gun not squeeze by hand) or is there something else you would sugest ? and what type of prep should i do to the glass? or is this a bad idea all together?