Thanks Peet. I calculate your sump capacity to be about 135 litres(?), so some lesser amount of water once you factor in baffle design etc. So with your 350L tank, you have about a 3:1 ratio of DT to sump. By the looks of your amazing growth, your tank's filtration is awesome.
I'm thinking of what size sump to go for with my 275L DT. I have issues with the dimensions in my cabinet underneath. The maximum length of sump I can fit in will be 50cm. Looking at off-the-shelf options, this will reduce the capacity of the sump perhaps down to 55L size. This will give me a ratio of 5:1, much less than your 3:1.
Do you think this will give me enough filtration?
BTW - I have 5 discus, a dozen rummy's, a dozen cardinals, 8 pandas and a BN, that my 2073 Eheim manages. I like the look of the wet-dry style. The sump (and return pump)/overflow combo i'm looking at will have a 1500/2300LPH flowrate so i think the turnover will be fine as this exceeds the Eheim. But i'd feel better with some expert re-assurance :lol: