Carbonator troubles

Hello again - If anyone has experience with carbonators, I'm using a lancer turbo (connecting to an antique seltzer bottle filler) and having scores of hangups - It's a high pressure unit and I keep getting blackish water, last night I realized I think the tank may actually be reversing the water back into my buildings old plumbing, oxidizing, then returning....is that possible? Is that an issue of the water pressure being too low, or a faulty regulator on the pump?
Any suggestions welcome, thanks -Webster

Cancel that - the answer was a bad regulator. Discolored water eliminated. Now I just need to get the water colder so I can amp up my fizz....

Are you sure it wasn't the Fetzer valve?