coarse sponge
less coarse sponge
filter wool
ceramic noodles or pumice
heater and return pump
clean sponges regularly in tank water
clean wool weekly in old tank water
Turtles can be dirty
It will depend on bracing that will support the table top to keep it rigid, that is a long tank and if the support isn't stable enough underneath could lead to cracking tank
being on 6 legs will allow flex in stand
do you have a pic?