No trays are not needed unless you have a filter that needs them as part of their design such as an FX5/FX6.
The entire Eheim Classic line 2213, 2215, 2217, 2260, 2262 and more have zero media trays.
No trays are not needed unless you have a filter that needs them as part of their design such as an FX5/FX6.
The entire Eheim Classic line 2213, 2215, 2217, 2260, 2262 and more have zero media trays.
I depends on the canister, what filter in particular are you wondering about? The rena filstar series needs the trays, since without them the water would just run through the pump without going through any of the media/filter material you put in it.