Salty, I've been keeping fw planted tanks for about 2 years. First off, most swords are slow growers as is. The only thing you have listed there that will grow pretty quick are the vals. They should be shooting out runners quite often as well.
You don't need nearly as much light as what Kim was saying. On a 300g tank, 1wpg would be sufficient even at 30". I know guys running 180g tanks with 270 watts of light growing high light plants. Judging by the plants you have listed, you have no high light plants. The larger the tank, the less light you need. If you put say 400-500 watts of light over that, you'd be going through ferts and co2 like crazy.
In planted tanks, everything has to be in the correct balance or you're going to have a big tank of algae. If you're going to boost up your lighting, you're most likely going to have to add co2 and if you're adding co2, you're going to have to add ferts. Having the eco-complete will help because it holds the ferts in suspension. Meaning the substrate soaks up the ferts until which time the plants will use it.
For a tank your size and if you don't want to have to add co2/ferts, stick with maybe 200 watts of t5 lighting. You don't have to go crazy with individual reflectors. That will be a medium light tank and although you won't have a heck of a lot of growth, it also will be pretty low maintenance. Dosing with the excel is going to get expensive on a tank that size although it helps keep the algae under control.
The bulb spectrum most people go with is just a normal 6.5k bulb. Depending on how many bulbs are in your fixture, maybe throw in a 10k just to give a little more pop to the fish. That's just a personal preference for many and doesn't actually do much for the plants.
Your ph is tied into your kh just as it is in a saltwater tank. A kh of 3 with a ph of around 6.6-6.8 is usually a safe bet for most freshwater fish. That is unless you're keeping cichlids. The higher your kh, the higher your ph should be. Knowing both of those will also help you figure out what your co2 in your tank is at. The more co2 you inject, the lower your ph will drop.
If you do plan on using fertilizers, make sure you go with dry ferts. It's MUCH cheaper then buying the premixed stuff. A good place to get them is from
www.aquariumfertilizer.com Here is a good calculator to help you figure out how much dry ferts you need to use.
http://atlas.csd.net/~cgadd/aqua/art_plant_aquacalc.htm
Just so you can see I'm not bs'ing you, here's some of my past tanks. Out of all of these, the only thing that I currently have now is a little 5.5g red cherry shrimp tank. I'll put the info of what I used.
29g biocube pea puffer tank
72w pc
Pressurized co2
dry ferts mixed with ro/di. Ferts used kno3, kh2po4, k2so4, iron chelate 10% and csm+b.
play sand from home depot/black flourite substrate
10g pea puffer tank over several months
65w pc
DIY co2
dry ferts mixed with ro/di and seachem root tabs
small pebble substrate
little overgrown lol
75g
324w t5 lighting
DIY co2
dry ferts mixed with ro/di
play sand/black flourite substrate
My very first planted tank 20g
65w pc
DIY co2
seachem line of ferts
play sand substrate
If you have anymore questions, don't hesitate to ask.
