Hello all, I’ve seen a second hand tank that i like and was told that a small dilution of bleach in water is all i need to clean the tank out. But i'm worried because the tank once housed tropical fish and i was wondering is there any way that my fish could become ill by being housed in this tank, even after I’ve cleaned it?

If you give it really good rinse, multiple times afterwards, until all the chlorine smell is gone, and then rinse some more, that is the most work involved. After that, have it sit a few days with water in it and a double or triple dose of dechlorinator, and you should be fine. You can gently scrub the sealant with a soft toothbrush (unused hopefully ) as an extra precaution...

Thank you!

Edit: what % of bleach to water should i be using?