While using my black tank flush

Guys here is what I know. Opened the black tank turned on the water and a slow stream came out of the sewer hose (water was clear) the other side of the rv were you gravity feed the fresh water tank it was pouring water out of it. That’s all I know

Jimbo

I suspect Chris3403 likely nailed the problem. Easy enough to mistakenly plug the flush hose into the city water inlet if they are close to each other and operator not paying enough attention. Still, since the OP has not responded with more specifics we are all left to just guess how that could have occurred.

From the way I understand your post is that by connection to the black tank flush
it immediately started filling fresh water tank which tells me it's labeled wrong.

Cross contamination from black tank to fresh water tank would be a disastrous plumbing error and highly unlikely given it's simplicity.

My Black Flush Tank connection is right above my Fresh Water connection.

Connections mislabeled? Post a picture of your convenience center, or where ever it is that you make the flush connections.
There is no connection between the flush system and the fresh water tank unless someone really screwed up the piping.

Mine have all been completely separate hose connections. I'm having a hard time understanding why a black tank flush system would have any connection to the fresh water system due to the potential for crosss contamination.

I would immediately remove and eliminate your cross connection if you have one vs a cockpit error. Then sanitize all fresh water hoses and tanks with heavy bleach multiple times. Then I'd still be leary of the fresh water safety.

Be careful and very repetitive sanitizing the fresh water tank if you decide not to replace it.

What kind of RV are you asking about? Is the black tank flush anywhere near the fresh water hookup?