I bought an Altman aquarium which is 98 cm x 43cm x 44cm.

Although the pump for filtration is inside the tank the medium is divided into three boxes on the top of the tank.
Water is then pumped onto the medium in the three containers, which finally goes into a bottom channel and into the tank.

When I bought the aquarium it had just three pieces of white mesh (not wool).

I would appreciate if somebody were to advise me, in what way the medium should be stacked in the container (eg. bottom - beads, on top charcoal and at the very top the mesh/wool)
I am very unsure about the order of the medium.
I am also unsure about the number of fish I can hold in the aquarium (presently I stock Orandas, Shibunkins)

I would appreciate if I were to get some advise rather urgently

Many thanks
David