As for the tank turn over rate, let do a simple calculation....
Main to sump turnover rate
7000(Red dargon 12000l/h after head loss) / 700 (net tank volume + sump) = 10 times
Main tank turnover rate
12000(tunze 6100) + 8000 (tunze 6080) + 6000 (tunzae 6060) + 12000 (tunze wakebox)/700 (net tank...