I wondered about the same thing...how does one measure what comes out of a black tank?
YOU can measure it coming out, I measured it going in.
I was born, raised, and worked on a farm. If this is the worse
thing anyone does in their life, they've had a pretty good life.
Or what goes INTO it, for that matter...?
Empty tank.
Mark a 5gal bucket at the 4gal line. Less slop this way.
Get water hose.
Start filling and emptying bucket.
Count buckets.
When full, buckets x 4 = gallons in.
To OP: maybe cheap, disposable camera on a string but I don't know if they have an exposure timer on them.
