When I did my Ventus (not a club plane) I did it with flying weight. IE I
started with me, flying gear, water ballast, drinking water, batteries ect.
in the plane. Being of sound ballast myself I needed to dump ballast to get
to gross weight. I did this with a stop watch and 5 gallon buckets under
the dump valves and had the "Weigher" tell me when I got to gross, stop and
record both time and gallons dumped, then continued to 9 lbs per sq ft,
stop and record, then dumped the rest. This gave me a very accurate amounts
in both gallons and time (seconds to dump for any wing loading I may want
to fly with.

Now I just time the fill time to half ballast and fly After all its a
Ventus and won't thermal worth a crap with full load

CH Ventus B
CH Ventus B

"If we are all "just dust in the wind", then I want to be at the top of a Huge Dust Devil!"