If you need to fill your cartridges, fluval and Marineland Type U blue foam are the best 2 materials to use in my opinion. Both can be found in pet stores in the aquirium section. Both of these are for the filter. If you try the blue foam, was
throughly with hot water and soap. Rinse completely and let dry. It has some sort of chemical on it. I'm sure it's safe to
vape knowing how touchy fish are but none-the-less, clean it. Soap and water will remove it. Pyramid tea bags can be used also. Search PTB in the forums. I wouldn't use polyfill found at wal-mart. Alot of polyfill is dipped in flame ......ent chemical.