The quantity should refer to the max capacity of your tanks. Say, 100L and then you’ll have to provide an average dump rate. Although I think newer version of the 90X0 have the ability to dump at different rates depending on how full the tanks are.
In your case you might say that you dump 65l/min to sort of split the difference. Then when you load ballast on your weight and a balance you put in 60l for example. When you initiate a dump for 30 seconds, it would reduce your wing loading by that 32.5kg.
I have found it hard to get it exactly right. But close enough that it’s workable for wing loading calculations.
Hopefully that is answering your question. It is worth having a good weight and balance set up for your glider.
It’s also nice to add a discrete switch on the dump valve that triggers the ballast dump. When you open the valve it immediately starts counting down.
Morgan
I'm trying to set up the glider dump rate function. I've measured the actual rates on the ground per 10L dumped, the rate starts at 9 secs/10L increasing to 12 secs/10L. The LX setup screen needs two values 'quantity' and 'dump rate' (l/min) - what value does the quantity cell require e.g. amount remaining, amount discharged etc? Tks