Thanks, Logan! I did look at your site first but I didn't see any tubing, or maybe I missed it! Anyway, my husband knew what you were talking about at Lowe's. (he's a regular there
) He says there are big rolls of cut-to-length tubing there and we'll take the top of the rigid tube with us to make sure of the size. Just one question: Some of the tubing has some writing (brand stamp, etc.) on the outside. Could this be harmful? I don't think so -- the tubing will only be in the aquarium for five minutes, but just checking!