Those that have replied with WC via sump ... this question applies to you:
Do you ever have to clean the wall tank of your DT then? If so, I assume you don't do it at the same time with this WC process?
The reason I ask this is because if you're doing it via sump, meaning DT will always be at full capacity ... so it would probably harder to stick your hand/arm in to clean the tank because it will spill.
I hope my question does make any sense.