Can the valves be left open while parked?
Grey tank, yes.? Black tank,
no.
At what level should the tanks be emptied?
Black tank 2/3 full.? If short of that, fill to 2/3s with a hose. Grey tank, anytime.
How is the best and most hygienic way to dump holding tanks?
Just before dumping, close the grey water tank and allow it to fill to about 1/3.? ? At that point, if the black tank is 2/3 full, open the black tank's valve and dump.? ?
When the black tank is empty, close the valve.? ?Now open the grey tank's valve and let it dump.? That will act to clean the sewage out of the sewer house -- grey water will be soapy but you can urge it along by adding a few squeezes of soap before dumping to aid the cleaning action.? ?Close the grey valve if you are going to move on.? Uncouple the sewer hose at the tank end, keeping it elevated wash it out with water from a hose.? ?Now uncouple it from the sewer coupling, remove the terminal plumbing wash, and stow all away.? ?You should wear heavy rubber gloves for this whole procedure -- I like the ones sold in hardware stores for chemical workers.? ?Keep a gallon of ordinary bleach and a small, 2-gallon bucket handy for cleaning up accidents.
Should chemicals be used?
Not really.? Your black tank is a septic tank, and septic tanks work by biological action:? gazzillons of liddle bacteria chewing away.? ?Chemistry generally acts to kill bacteria -- that is why most contain formaldehyde.? ?You may want to encourage the little rascals by adding some septic tank bacteria, stuff sold in septic tank country, but I never have.? ?Grey tank stink can be cured with a bit of bleach, or simply dumping.
And as John said about tissue -- fergit the RV store TP, use Scotts or another paper
approved for septic tank use. See also the latest exclusive RVForum TP tests.
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