Ha my filtratoin system was probably close to 200g.
But you guys arent doing a 6000g pool either.
I could post pictures if necessary...Ill try to keep an eye on this post. Doing this is possible. So long as the bottom doesnt inflate the bio tower is probably the easiest method.
When I did that I took a large garbage can, Filled it with scrubbies, had a tray up top with filter floss that doubled as a drip tray. The bottom had holes in it, and also was weighted down with a cinder block. Then a sump pump in the pool pushed water to the top where it was mechanically filtered by the floss, then dripped into the scrubbies, which actually also acted as mechanical as well as bio filtration.