Ah... ok.
Funnily, when I added 30m extension, I kept getting DE error, basically the pump thought there was a blockage. Recalibration seemed to fix it though. I think whenever we change a way of working, it throws up issues that we have to resolve.
I will be following you soon with a tank and reel. At the moment though I don't earn enough to justify it, but leafleting like mad now. Picked up 21 new customers so far this month.