Is it not cheaper to simply use the largest van tank you can find ?..........rather than start up, and buy a 250/400 baffled tank... and then go to the extreme of buying tanks for garage or butts, as a back up......tubing and submersible pumps to transfer it to your small empty tank....
i may be new and fast outworking my 250 litre tank... but rather than go to those extremes i may simply buy a larger tank.... too large...... but having learned from my mistake, is it not less hassle and much more simple?
by the way , this post is for the one man outfits not the people who have lots of men working for them,..( or is that the aspiration of many?)
as its obvious back up tanks are essential...
cheers
Gary.