You have really taken your time with this tank. I have the same one and wanted to do what you're doing. I decided I preferred instant gratification and had it planted and filled in about a day.
Did you switch the stock bulb? You can get a 9 watt 6,500K bulb at home depot for a few bucks. Make sure you get the one that says G23 base if you decide to get one.
Malaysian Trumpet Snails: JUST SAY NO!