Black tank question

Doug33 wrote:
For sanitary reasons I find it hard to believe a shower would drain to a black tank. Frequently when using the shower while boondocking, my grey water tank fills up completely and the shower will not drain. If the shower drained to the black tank, wouldn't I have black water tank contents floating up into the shower????

That is how we found out my son was in the shower and said "Dad it ain't draining" I had him get out and I looked at it, brown water. Went out side oped the the gray, but that didn't drain the tub. Went to a rv place bought a tank, drained the black side and tub drained. Cleaned it all up and told him not to use shower. Dealer wouldn't help me out said they don't make them that way. GulfSteam also denied it. We figured out how to use it safely, but what a pain. Now every dealer I am talking to about my purchase (bigger and better) say that none of what they sell do that. I ain't sure I trust any of them because even after the fact my dealer still thinks I don't know what I am talking about. Will not buy from them and they have have the best prices. from the replies I am getting I must be the only one on the planet with a camper set up this way.