That's awesome Heidi, looks good, great job.
I also prefer to just let them grow.
Did you know that light reflects off the glass and can actual have a positive affect on those polyps even though that aren't getting a direct down spray of light? I sat in on a seminar about 4 years ago in Atlanta and listen to an awesome presentation on this. I will try to share the full story and details if I can find my notes and the actual video.
Good luck with the ZPs.
Mooch