No clue what "get fed up on my concrete break wall" means, however one possibility would be get a can of that rubberized stuff they use on handles of tools or to waterproof electrical connections and paint a few coats around the bottom of the tank.
A better solution would be to sling it which is better than backmounted for many reasons that have been cited many times on this forum.
Concrete break wall, I dive off my property in shallower water.
This all works great for my needs. I spend time metal detecting and looking for artifacts of interest. I get about 1.5hrs of dive time.
I have many steps to go up and down so I am fine with small pony and one tank. Others have made dive set up suggestions.