I have a 75 gallon tank standard size with 2 oscars (under6'') an a jack demp (around 5'') with a rena xp3 water looks like crap 3 or 4 days after a water change am i rinsing the foam sponges out to often or do i not have enough media in the compartments? only have the sponges that came with the filter an a bag of carbon an some bio stars only the media that came with the filter not enough to fill all 3 bins any suggestions? An please don't tell me to get a new filter.....