I probably should've put this in my first post but i do work seasonal at a large seafood exporter. Handle live crayfish, king crab, abalone and some other species aswell.. Predominantly my daily tasks are tank cleaning, water testing, water change outs, bio filter maintenance, skimmer cleaning (uurk), stock rotation with a fair bit of driving in between picking up fresh stock for market and export.
Our bio filters are huge.. 3 of them are 5k gallon tanks and another is open top tank 10x10x5 ft. typical build method is milk crates stacked on the bottom, plastic mesh then 20-30kg bags of shale and coral cross stacked over the top, 4-5 layers of.
Sry i have not got any good photos of the tanks, but here's one for ya's.
Plz excuse my cheesy grin