All the media in my canisters for planted tank are arranged this way
Bottom tray : Eheim Efhimech ceremic rings as prefilter. Helps trap large debris and break up water current into all directions. Better for the bacteria colonies to do their 'thing'. On top of the ceramic rings, i use coarse sponge to trap the smaller-finer debris.
Middle tray : Eheim Substrate full tray for pure bio filtration
Top tray : Eheim substrate pro, followed by fine filter wool on top to trap all the much smaller and finer particles, before the water is released back into tank.
Some people prefer to use fine filter wool at the bottom tray, to prevent the other media from dirtying too quickly. I personally find that this will somewhat decrease the flowrate and will have quite an uneven flow through the canister. But then again, trackback to the point is that they want to have cleaner media. It's your preference
Hope this helps. Goodluck!
|