Hey Teresa,
Would like to help, but not sure how much I can. Is this tank glass or acrylic? Is it glass with an acrylic front or ???
If it is all acrylic, you will have to get some Weld-on #16(i think) and you should be able to fix it in the leaky spot only.
If it is glass, Slicone I (i think, the one without mildicide) for silicone application, I would replace the entire seal for that section. Don't know that you have to, but it would mke me feel better, if it were my tank.
Maybe someone smarter will chime in here. Sorry about your tank. Good luck!