Taking Mature Media From One Tank To Another

[AN1M343V3R]

how do i do it, ive got a 48l tank set up and working nicely with a interpet PF1 and ive just got a 4ft tank and an external filter on the way, how much of the sponge within the PF1 should i cut/take and put into the new filter without harming the other fish and would i need to replace the bit i took with more sponge?

 

[england]

Is there much filter media in that filter, other way is too take the media out, squeeze into a container, then soak new media in it for a while, then place in new tank,