Looking for some advice on filtration

[on4now4]

Hello,

I am working to get my new tank setup. A 170 Gal Fresh Coldwater tank. I am planning to use it as a simple planted and goldfish tank.

Anyway my question is about filtration. I am looking heavily into doing a sump setup on the tank. But from everything I see it appears that all I need in my sump is a couple layers of foam for mechanical filtration and then a bunch of K1 or other similar bio media. Why do canister filters have so many layers in them? Am I going to get enough filtration with nothing but foam and K1 assuming the proportions are enough.

 

[Delapool]

Gives the owners a number of trays to experiment with lol.

I have two grades of sponge plus final filter wool (coarse to fine mechanical filtration) and also bio-media. As long as the bio-media isn't getting gunked up too badly is my usual rule for filter experimentation. Some people also run purigen or carbon so the trays do give a bit of flexibility.

 

[Rpeinhardt]

The advantage of a canister are these:

1. Potentially smaller than a sump
2. Closed loop, no need for an overflow in the display tank.