Off a derro lol I just imagined someone walking around with a shopping trolley and a turtle tank in it. 2000Lt an hour is a lot, should be clean hahaha. Advice, well you seem to have it sorted, Im guessing you know about diet, keeping fish with it, health etc? Myself I dont use normal gravel for a few reasons, turtle grit and river sand is the way to go. Im guessing you know about australian freshwater turtles site? Great care sheet there and heaps of people that know a whole lot more than me.. yet.. hahaha.. Ah Im jealous your in QLD, we cant keep painted turtles here and I really want some. Are you planning on keeping him in that tank or building a pond? I started building my pond but winter hit so I have put it off for a few months. Turtles are great, so funny and active.