(3 Pack) Nitrate Reducing Media Pad Aquarium and Pond Filter Accessory, 10-Inch by 18-Inch

I had rising Nitrate levels all the time. Got this and after a couple weeks it has stayed stable ever since. Reduced water change frequency. Really good at capturing everything. waters always clear. You cut them with razor knife and you get a lot of usable pieces from each sheet. With the 3 packs of sheets each filter cost almost nothing. Replaced entire filter in my small Aqueon and added it on top of my Agua Clear filter set. So I rinse them after 2 weeks and toss them when I clean tank at 4 weeks.