with regards to nose weight, do many people carry a 2nd gas bottle in the caravan ? also does every one drain there flush tank for travel ? again to drop nose weight ?

I normally have one 6kg + one small, no onboard fresh water tank, usual plastic barrel outside but a hot water heater right at the very back of the caravan which gets drained down when traveling. Flush tank, not quiet sure of the capacity but normally have it around 3rd full when travelling for any emergencies. But i might have to take my 2nd bottle out & check other bits