How deep are you making the false bottom? You may want to reconsider the false bottom since this is a small viv and think about using large stone fish tank gravel or a bag of hydroballs which will take up less of your bottom. You can get away with probably a 1 inch deep gravel or hydroball layer and then the moss layer with a layer of plantation soil or eco-earth on top of the moss.

You may even not want the moss layer but I like it for the moisture retention which should help with the tanks need for higher humidity.