The nitrate level is high but not horrible. If you get some plants in there and do a 30% water change every couple of days the nitrates should come down. That is if the nitrates aren't coming from the tap water. Test your tap water for nitrates and Gh and Kh and whatever else you can test for. It's important to know what your tap water is so you can know where the stuff in your tank is coming from.
GH of 8-9 is fine for plants. Some of these plant books were written 5 years ago or more and the hobby has gotten much more enlightened since then.
Get a Kh test. Crucial for determining CO2 levels in your tank and buffering capacity of the water.
Do you have your tank specs listed somewhere? It would help tremendously, so that we can steer you in the right direction.
FILSTAR Pimp #2
75 gal heavily planted,50/50 Black beauty,Eco-complete substrate, Pressurised CO2 with solenoid, ph controller, AB Reactor 1000, 330 watts 9325K GE PC lighting,Ehiem Liquidoser, 2-Filstar xp3 canisters.