How long will a new filter take to mature ? (fully populated tank, post-disaster)

Hello,

We have a 220 litre cichlid tank that has been running happily for
several months now (see http://fish.alansilver.co.uk/Mark3/). It was
running an Eheim Ecco 2235 filter, but I wasn't happy with it. I had a
lot of trouble every time it needed cleaning (which was far more
regularly than I had expected). I was very unimpressed by the poor
design of this filter and had a lot of trouble restarting it each time.

Well, the final straw came just over a week ago when the priming handle
broke whilst priming the filter. Of course this happened about 5pm on a
Sunday, when all the shops were shut !! I put a Fluval 2 from the other
tank in, just to keep the fish alive until morning. I also dropped all
the sponges from the accursed Eheim rubbish filter (grr) into the tank.

We got a Hydor Prime 30 (http://www.hydor.com/inglese/prime.htm) which
the man in the LFS said he had been selling for about 15 years and was
very happy with. This was a different world from the Eheim. Instead of
hours of frustration and fiddling, it just plugged in and worked !!

Anyway, so we now had a brand new filter running on a fairly well
populated aquarium. There are about 28 2"-3" cichlids in there. I have
left the Fluval 2 in for the moment and have cut back the feeding whilst
the new filter matures.

My question is (after all that waffling !!) how long do I need to keep
the sponges and Fluval 2 in and how long before I can go back to a
normal feeding regime ? So far all looks well, but I'm being fairly
cautious here. I haven't done a water change since the disaster either.

Any advice or comments welcome. TIA

--
Alan Silver
PSG Fish Tanks - http://fish.alansilver.co.uk/