All of my tanks are planted and 2 are doing well. The betta tank though is a 5 gallon tank with water sprite and a floating lilypad type plant. While the plants are living they are not really growing like the other 2 tanks. I use an iron rich plant food once a week like the other tanks and the light levels are 3wpg. Since the betta is the only fish in the tank I assume that the nitrogen levels are too low. I can't test for nitrates right now as I only have an ammonia test kit. What is an easy way to add nitrogen to the water. I don't have easy access to any plant ferts where I am living at the moment. The next time I head to "the big city" I will be able to get some bottled fertilizers and probably excel as well. As it will be a few weeks before I can do that is there anything I can add until then?