Today I did something I don't usually do until my roommate nags me enough. I purchased a new furnace filter. I know, big deal! It's the sort of thing I just never think about and then when I change it -- ewwwww! My air cleaner takes the large 16" x 25" x 4" filters. I'm always forgetting which size it is so today I put it on my smartphone so there are no excuses going forward!
Here's the old one. Guess it DID need replacing after all:
Brand spanking new filter:
You can tell the difference, right?!
So let that be a lesson to you -- if you've just turned your heat on, like me, get yourself a new filter!