I have the sundial on my 29g and it works well. I keep a bit of everything including some sps in the top 1/3rd of the tank under the lights. The bulbs it comes with aren't great but they get the job done for awhile. If you want a fixture to sit on legs over the tank Sundial is really your only t5 option. If you want to hang a fixture, a tek 24" would get the job done better and you can pick your bulbs.