I disagree with Rogo, you can add plant in fishless tank even the tank isn't cycled. As matter if your tank is heavy planted, you don't even need cycle first as long as you don't add all the fish in at once. (which is always the case as you need to add fish in slowly to allow bacteria catch up even if your tank is cycled.) I never pre cycle my tank when I do planted tank.
Bacteria not only live in filter media, but also gravel and plants. Plants will also use Ammonia , nitrite and nitrate.
You are also not going to kill fish if you have 3 neon tetra in 33 gallon tank.
You can also add seachem stability if you don't want to wait the tank to be cycled.
