That's not what sainthogan meant at all. He didn't mean you should increase them. He meant if you're not having any your tank is not cycled. This might help: http://www.bettafish.com/showthread.php?t=47838
You will see nitrates during cycling. The plants will eat some but they will not likely keep levels like this..Some plants don't even eat nitrates, others do to a certain rate but if you've only been changing 10% a week it would be extremely unlikely to have those readings. How long have you had the tank set up? Cycling takes up to 2 months to complete, during which time you needed to have been supplying an ammonia source (like drops of pure ammonia, fish or fish food), so how long has it been set up with an ammonia source?
Can you share pictures of your tank please so we can get an idea of how heavily planted it is?