How much water to ad to black tank when starting out.?

Grit dog wrote:

Terryallan wrote:
When we are ready to leave. I dump, and clean the tank, put in a packet of Camp chem, and add 5 gallons of water. I leave it there until the next time we need to dump while camping.

Do you measure the 5 gallons?

Sincerely,
-pianotuna

The bowl holds right at a gallon of water when filled. I fill, and dump it 5 times. Thankfully. Our bathroom has a door to the out side. So I can use the hose to fill it, and not have to wait for the flush valve to do it.