Hi forum members,

I have a Rio 110 Wet/Dry power filter. It seems alot different than the filters that were being discussed in the pinned article above. It doesn't have a wheel or anything, it has a "prefilter" cartridge, then two additional mediums, one that looks like carbon foamy type stuff, and another that is a box with a white paper like substance on one side (I am not sure what is inside). It is advertised as having "Rain system for extra aeration, dual biological filters, carbon filtration, mechanical filtration, flow up to 110 gallons and 400 liters per hour." The descrption of a Wet/Dry filter here on Kokos doesnt sound anything like this one as it hangs over the back of my 10 gallon tank. Anyway, while I was doing my water change last week, I noticed that there were green spots all over the white side of the cartridge that was visible. So, I took it apart and rinsed out all of the mediums, because they looked pretty nasty, but i couldnt get rid of the green spots. Then I dumped the water out of the area that it collects in because it had big chunks in it. Perhaps I wasn't supposed to do that. So then I called my LPS and asked them if I am supposed to ever change the filter medium (I have had it for about 3 months), and they told me I should do it about every 3 months. So I went there today and they do not sell any of the replacement medium. I searched online, even looking at the big chain store websites, and I couldnt find the replacements anywhere. So I came here and read some of the posts in the pinned article above about filtration, and now I am wondering if I am even supposed to change the cartridges, ever? And if so, should I jsut get a different filter entirely since I can't find the replacement cartridges for this one? and if I replace it, what should I replace it with? I have gotten so much non- and mis- information from the LPS that I don't trust what they have to say because I think they will say anything to get me to spend more money there, even if it means the life of my fish (whom I love dearly). Which truly sucks because they are the only pet store in my area and I like to support local businesses. Plus I don't like the idea of getting on a bus to go buy fish supplies. Any advice you can give will be greatly appreciated.
Thanks for reading.

Confused and misinformed,
Rachael