Need filtration advice urgently

[FTS]

Two Eheim 2217 or one 2260 for 400L ?

 

[japes]

I'd have to say a 2260 for sure, rated at over twice the output of the 2217's, the equivalent capacity of almost 4 2217's..

Only thing is the 2260 isn't supplied with media, so you'll have to sort that out which will cost you extra.