Hey tank islooking really good, to be honest I chucked all of the sponges away after the first few months instead I put a large bag of siphorax in there and on top of this I use some White polishing foam the sponges slowed my flow rate and were a nightmare to keep on top of. This is probably the best change I made as the flow increased and maintenance now includes lifting the bag out and giving it a rinse every now and then, simple!! No more blue pad this green sponge that, hope this helps, also don't buy new sponges as often as it says by juwel just rinse out the ones in the tank in water you have taken out of the tank during a water change to get rid of the mulsh build up, never rinse under the tap as the chlorine will kill off the bacteria you should only need to replace them when they fall to pieces!! It's a con trying to get you to spend more money