Well an accurate figure would depend on the weight of the substrate and rockwork....as a ballpark 400 litres of water would weigh 400 kgs.
I don't have the Rio but I do have a Trigon 350 which uses the same Jumbo filter. Juwels are well made tanks, well regarded. The filter's OK without being brilliant, 3-stage sponge filter basically, depends what you're going to use it for. I keep cichlids and double up filtration with an Eheim canister. I have to say that I'm happy with mine.
