Reinforcing toilet/shower/black tank combo

Hello,

This is my 1st camper and I have learned a lot from this forum so far... thanks!

I have a black tank drip from either the threaded pipe going into the tank or possibly the flange on the tank. I pulled the toilet first (need to change the seal) and I noticed that the tank was bolted to the top of the tank with no flange. This method of mounting allows the toilet and tank to flex a lot. I am worried about this cracking the tank. Is there a way to add strength to tank?

Thanks,
Mike