I agree with Mooner. I have an Eheim 2028 on my 100g, I tend to check it out approx once a month. I generally quickly rinse the coarse sponge & 3 trays of biomedia to get rid of the course rubbish. I replace the final white foam as well with polyester filling from the local fabric store (much much cheaper than the original Eheim sponges). Then it goes straight back on to the tank. The murky contents are usually tipped into a large container where my wife will spend the next hour saving the fry, baby ghost shrimp (last time she found 68) & others that have found their way into the filter.
That's the easy bit...cleaning all the hoses (including UV, heater housing & the pickups & piping running under the substrate) is another story...
