Whatman filters


Ok im having a hard ass time getting this stuff to filter thru these whatman filters. I included a picture, and its almost like there is gunk getting clogged in the filter thats blocking the tren from dripping thru. I apply as much pressure as i can and it still doesnt do any good. I have a few filters, and i just swapped the one i was using for a new one, and at 1st it works real good and filters thru quick quickly, but a minute or so into it, it starts getting super hard, and dripping slower and slower. any clue is to whats going on here? im thinking something is clogging the filter, i cant imagine it would be anythig else.