Fertilisers in your tank

Yes I've been at it again so have posted my 3rd YouTube clip!! This new format takes a lot more time, but I feel it's worth putting in the leg work. My editing is not the best but bare with me as I improve with experience. For those of you interested I'm using iMovie for editing but would like to invest in decent lighting, a background, HD camera and decent mic to avoid the sound delay.

I'm discussing fertilisers in the planted aquarium and which type you need for low tech and high tech tanks. I hope you enjoy the short clip and would appreciate any feedback.