ok so first off i hope this is in the right place, thinking since its trying to fix a leak that would be considered diy. anyway to my problem. i got a great deal on a 75g and 40B but both leak from the bottom. i have never resealed a tank before so am a little nervous and not sure how. i have worked with silicone before just not trying to seal something that i plan on being filled with water in my home. i know that new silicone doesn't stick well to old so am i correct in assuming i should remove all the silicone in the tank? also should i remove the trim on the tank to do this? thats another thing i have never done before but can't imagine it being too hard. one last question, the 40B that i got has what appears to be a center brace on the bottom trim that runs under the bottom glass, is this normal? i don't think i have seen a tank like that before so figured i would ask. if anyone has any advice please feel free to share as i am a complete noob at resealing tanks. thanks