hi
to protct the lives of you fish,as your tank goes through
the cycle,you can preform small water changes,but Please
don't touch your filter as that is where your bacteria is growing :)
once your tank has cycled then you can have a maintainance
of filter cleaning once a month,remembering never to wash
anything in Tap water,and never replace all filter material at one time,as this Will kill your bacteria that has grown.(you will have to re-cycle)
amonia burns the gills of the fish,and nitrIte poissons them
(if i'm wrong here i am sorry)
you can watch the fish for Red gills,also gasping at the top of the tank
that's a couple of signs that they are suffering.
if you have a friend with a tropical set up,you could always ask if they could spare a filter pad,as that would help your tank. :)