Josie:
First, thanks for the great deal on the K1 media and instructional video. Well, I made mine and it has been in the tank for about 5 days, waiting for it to get gross. Only suggestion I have after watching your video is to make the top holes higher as the height of these top holes govern the max height the media will tumble. If they are too low, the top of the bottle will simply fill with air, but the media obviously will remain at the water line governed by these top holes.
Here is a short video of mine installed in my adult tank. I will be making a 2nd one for my juvie tank shortly.
Cheer,
Darren