Gurgle Garden not working

[Tim]

Ron, I put together Gurgle Garden that I saw hyperlinked on page 14 of your bulletin board. My pump is definitely powerful enough, but water doesn't make it up to the top of the drip area. I used aquarium tubing, etc and followed the directions as depicted by the diagram. How does air forced into the solution through the tee in turn forces solution back up into the tube connected to the same tee? Any ideas on what's wrong? Thanks.