With a shallow tank like a 20L your probably fine with the Finnex 24/7. It's will have enough power for most plants. If you don't care about the bells/whistles than a twinstar is a good light, but don't know if it comes in 30". I actually have a 30" Finnex 24/7 CC suspending over my tank. Once you learn the remote, it's pretty easy to program. I also have an ONF Flat One that has bluetooth but I don't think that comes in 30". Once set I barely use the remote (Finnex) or my phone (ONF) via bluetooth.