Hey, I've never seen or thought of a tube in the tank before! That is a nice item. Have you used it in the past? The tetras really go through, huh? That is all I have just now, 16 tetras - neon, pristella, and black neon. Very nice set up. I tried live plants a few times, about 7 years ago. All I succeeded in doing was making a great big mess. So I stick with the fake plastic stuff now. I like what you have there.