The 3” RV drain hose — also known as the “Stinky Slinky” — is a very important RVing tool. Therefore, when you arrive at your next RV park, take a few minutes and do a proper set-up of your whole RV waste disposal system.
“How do I drain my tanks in the most efficient manner and not slow down water flow which kills suction?”
The best way to drain your tanks is to set up the hose with a proper grade. It should be higher at the RV side and lower at the dump side (the part that goes into the ground; where the RV park or resort collects waste material from each site and then sends it on to a local storage tank, leach field, or the municipal waste handling/processing system).
Whether you use an articulated bridge, ramp, concrete blocks, or even rocks, when you do this, you are taking full advantage of gravity flow and the suction that it creates.
The best way to increase tank flow suction would be to never empty your tanks until they are at least 3/4-full to completely full. This creates greater down pressure and sucks the debris out of the tank.
And remember to always empty the black tank first then the gray to clean the hose.
Another benefit of using bridges and ramps in creating proper grade is that you keep your stinky slinky off of the ground, adding additional life to the hose and keep it free from holes.