Re: another couple of water tank questions
the grey water tanks that i got out of several trailers and a motorhome all have 1 1/4 black plastic pipe for the vent.. In my bus, I put 3/4 inch tied together for the 30 gallon tanks and that works fine. I vent through the roof. The 3 inch roof vents are only a few bucks at camping world without the screen which can easily be stuck in there to keep the leaves and bugs out. Back almost 20 yrs ago, i started out with using 3 inch plastic pipe for all the plumbing, as it was mobile home code, and have slowly reduced things like vent size down because smaller size is far easier to install, and works fine.
Jesus Christ... Conversion in progress.