Hi, I have a 60L tank with a Fluval 2+ internal, and just want to ask a few questions about general maintenance. Question 1 - So the white corse foam blocks (2 of them) are the bits where the good bacteria colonise and keep the tank cycled and mature right? - I've read different reports on wether to and how often to replace these. I always thought as these were your colony homes, you shouldn't change them.......what is everyones thoughts on this?? Leave them? Rinse them every week? Change them one at a time? - If so, how often? Question 2 - The filter also came with a 'poly-pad' and a carbon pad, which you can sandwich in between the 2 bio-foam blocks. I gather the poly pad acts like a fine particle filter. I have so far cut them in half, and put half of each in at a time; so that there is half a poly pad, and half a carbon pad in together. Is this a good idea?, and again I'd like to ask how often these should be changed. I know carbon generally lasts about a month before losing its activity, would half a pad still last a month? Does the poly filter need changing (how often?) or just rinsing out every week or 2? And finally, just wondered what sort of volumes every else changes at weekly water change time - I tend to do a 20 - 25% change - does this sound good? Sorry for the big question, but we all gotta learn somewhere by asking those that know!!!