The tank I have was free. I'm setting it up and I'm noticing the filter has no beneficial bacteria insert. My question is can I use all Polyfil inside the filter. The filter is a standard aquaclear hob filter that comes with the Wally-world 55 gallon kit. Also is ployfil a generic term because all I have to use is pillow filling that they sell at Wally-world. Thanks in advance.