What type of fertilizer is best?

[keydiver]

Ok guys, so I have a 40G discus tank, lightly planted right now, and I'm going to upgrade the lighting fixture(thought I might try to get it right this time). I thought I might get your opinions on which type of fertilizer is best. I'm planning on planting it more heavily once I get my new lighting upgrade, but as of now, all i've been doing is adding liquid fertilizer, and the plants seem to be doing fine. I was wondering if I should add the fertilizer that goes under the substrate if I want to do a heavily planted tank. Also, I don't know how I would do that in an already established system(I'm going to have to add more gravel as well). My stocking list now is java moss
java fern
wendtii crypts
anubias nana

New stocking plans might include
various swords
baby tears or some other type of light loving ground cover
vallisneria
wisteria
sagg
micro sword
And give room for pretty much any low maint. low light, med. light, and high light plants that all add to the blackwater/discus biotope

Thanks for reading, opinions greatly appreciated

 

[keydiver]

anybody?

 

[VNCNT]

pfertz and root medic offer packages for low tech to high tech tanks. i think you might only need macro nutrients (NPK) nitrogen, phosphate and potassium...