So I have read I think 300+ posts on the issue of what to fill your cartridge with? I tried the tea bag, the paper towel, the coffee filter (all things I had in the house) with different degrees of success. I'd like to try the Fluval but Fluval is a brand name with tons of products. So if some one can post the exact name of the product (ie: Fluval Foam Inserts or Fluval Water Polishing Pad or Fluval FX5 Fine Filter Pad, I could keep going) or a link to it on petco or something that would be great. Also in some of the posts I noticed that some are combining the fluval with the tea bag... I have a 510, if someone could give a step by step on how they are using the fluval (with or without the tea bag) that would be great.