Originally Posted by djmers
We are very new to having an RV and learning the sewer system. Regarding black water tank, when using the parks sewer system, should our black tank be at 1/3 full? I thought everything should pass through. Thanks in advance for any help!
The liquid will go through and the solids will remain behind if you leave the valve open. Most will leave both valves closed and empty (dump) the tanks as necessary. You will want to dump the black water first and then empty the gray. That way your sewer hose will be somewhat cleaner than if you dump the black last.
If you are staying for a week or longer you may wish to jeep the gray valve open and draining, then a close the valve and store gray water a day or two before dumping the black.
There are several different schools of thought on products to keep down odors than range from nothing to DIY concoctions, and commercial liquids and powders. I've been happy with Happy Camper powder available from Amazon.