Flex Seal or similar for repair?

[Sstadler]

I became the owner of a 75 gallon tank that was free but the bottom of the tank has a crack with a leak. So a thought had crossed my mind for tanks that have some damage. It looks didn’t matter, like maybe I was using tank for sump, could I flex seal the entire bottom of the tank? Would it still work? Or what if it was a DT and I flex sealed the bottom? I mean, no one really sees the bottom of the DT anyways, right? I can’t be the only one who’s thought this so why am I wrong?

 

[Mjrenz]

I personally wouldn't risk it, even if you get it to hold water the bottom panel is still cracked and not structurally sound. That's a lot of water and a lot of pressure pushing down on an already cracked pane of glass

 

[Zar]

It depends, if the tank is made out of acrylic then yes you can seal it, but i would use another acrylic sheet on the top and bottom and seal it together. Don't get me wrong, flex seal is a great product but over time that adhesive comes off underwater.
If it is glass, just know it will be a risk short / long term.