Originally Posted by Paintinfool3
only hook up to dump tanks when they are close to full ... I wouldn't leave it hooked up .... tanks need water in them to dump especially the black tank so let them fill then dump when they get close to full
I certainly don't wish to be argumentative, but you can leave the dump hose hooked up, but leave your valves closed. And not having to haul out the dump hoses and hook up/unhook/re-stow every time saves me a little time.
I typically leave my black and kitchen grey tank valves closed, for the reasons noted by others. The bathroom grey, I typically leave open. With showers, washing hands, brushing teeth, etc., the bathroom grey tank tends to fill up pretty quickly. Because I use paper plates, I only need to wash pots & pans, glasses, silverware, and cookware every two to three days. That means my kitchen grey tank fills at about the same rate as my black tank - about 4-7 days (depending on what I cook . . . and eat).
Since I'm staying long-term at my full-hookup site, I have a little routine I go through each time I dump. First, I raise my stab jacks so I can rock the trailer to agitate the tanks. Then, I close the bathroom grey tank valve. Then, I rock the trailer to stir up the juices in the black tank, and open the black tank valve to dump the tank. I, also, leave the clear 45-degree elbow installed (on the trailer dump pipe) so I can closely monitor the flow. I've found that just because the flow stops, it doesn't mean the tank is empty; sometimes it means there's a "minor" plug. Once to flow stops, I turn on the water to the flush hose (which I also leave hooked up to a "Y" valve with dual shutoffs). Sometimes the agitation of the black tank flush will break loose a "minor plug"; sometimes, not so much. If not, I'll close the black tank valve for 30-60 seconds with the flush water running. IMPORTANT: DO NOT GET DISTRACTED AND LOSE TRACK OF THE TIME DURING THIS PROCEDURE! This forum is replete with posts about the nasty things that happen when you get distracted during this procedure! I then rock the trailer and reopen the black tank valve for dump #2. Once the flow stops (or significantly slows) the second time, I reclose the black tank valve and allow the flush system to work a second time - this time for about 60 seconds. I re-agitate, re-dump, re-close the valve for another 90 seconds. If this dump water doesn't run perfectly clear, I'll reclose the valve and run the flush for another 2-3 minutes; then repeat the agitation, and reopen the valve. When the water going through the clear elbow runs clear, I shut off the flush and allow the tank to drain. Once the black tank is empty, I close the valve and dump the kitchen grey to clean out the line/hose. Finally, I reopen the bathroom grey valve and go inside to check the tank levels on the sensor board. I've found this "4-flush" procedure keeps my tank sensors working perfectly.
One thing I have noticed is that on days when there are a lot of people dumping and leaving the campground, I do get a significant amount of odor coming out of my grey tank vent . . . as a result of the increased sewer-system activity. So, I just close that grey tank valve for a few hours until the activity dies down.
I'm not saying this is the only way to do it, or even that this is the best way. It's just the way that works best for me. It might (or might not) work for you!