Um, I have a different method of fertilization that has always worked for me, and I have had aquariums for over 15 years with live plants-not trying to be a douche or anything, but fish crap works great. Here's how I set up a new tank- Gravel, water, fish. Add some dechlorinator and balance the ph. Next step- never touch the tank unless you are adding water-then add some dechlorinator. I use some Easy Balance(Tetra product) when I add water as well. I never change the water, rarely change the filter, and have a ton of fish that are completely happy, as well as such rapid and luxurious plant growth that I have to periodically chop them back as they block the view of the fish. My method is the live and let live method, and as far as I am concerned(no offense to anyone, I know there are lots of people who know way more than me about aquatic life), plant fertilizer, ph balance, ammonia tests, etc. are a waste of money. I say ultra oxygenate, ultra filter, tons of plants, tons of fish, and LET IT BE.
I apologize to anyone (probably everyone) who knows more than me.