anyone have any experience with these filters? I checked mine on my last partial water change I noticed that the filter was flooding and pouring out of the top, so I removed the filter pad and noticed that it was bulging and has covered in all I can describe as slime. Swishing it around in some of the old tank water did nothing, water wouldn't even penetrate this slime. So, I put a new filter pad in, I know, I just killed what little bit of a cycle I had started, but is this normal for a filter pad? Any help would be greatly appreciated