Overdosed on Alk.

[7hogwarts]

This happened quite awhile ago. My dosing unit sent 3 gallons of Alk into my 125 gallon tank. I did multiple mass water changes. Lost most of my corals.None of my fish.
The tanks parameters have been fine for months. The corals are growing and the fish are fine.
Now for the problem; the sand bed turn into a brick. I can't pull it out or break it apart. I figured with time it would go back to sand. I am afraid that I may have a capped bed that might be a time bomb of anaerobic bacteria that is waiting to go off. I thought about possible trying to get a probe into the brick sand bed and do small doses of vinegar to break it. I'm not sure if that wouldn't create a bigger problem. Any help and/or thoughts about correcting this?

[bertoni]

I can't think of anything to do other than tear the tank down. I don't think adding vinegar to a running system is going to be practical, as far as breaking up the sandbed.

[7hogwarts]

Thanks anyway. I was hoping someone would have some sort of fix. Since all the corals are currently doing fine, I won't do anything. Although, I may try adding some sand to an area for the sand burrowing creatures.