If I'm not wrong, that's in the Ocean's dreams arc, right? The one where everyone save Robin lost their memories? Yes, it is filler, you may skip it
Besides a little, mysterious quote from Robin towards the end of the arc, there's nothing significant for later chapters ^^ I actually just skipped all the fillers and watched them after I caught up with the anime and manga and had nothing else to read/watch XD (And I wanted OP!)
Oh, where does it start? Well, after the arc's over (episode 224 is the last filler one) comes the Aokiji arc. However, episodes 225 and 226 are also filler, in which the straw hats run into Foxy, Porche and Burger. If you're interested in what happened to this characters, you can watch this, it's actually really funny and just too episodes.
Also, the Aokiji arc starts on the second half of episode 226, so you kind of have to watch it XD And Aokiji arc is canon and very important so... yeah, you can't skip it XD
Hope I could help! Whatever else, just ask!