I have a few questions some the same as the above poster. What is your stock? What size tank? What's your filtration like, can you post a full tank shot? Are you over feeding? What are your water changing schedules like? Plants will help BUT... Will not solve the issue at hand. It's better to figure out what is causing your readings. Also how high are we talking?
I had a nitrAte issue in my 76 gallon African Cichlid tank it was reading 180+!! I did 75% water changes for a week, cleaned all filters an gravel vacuumed the substrate. Still nothing 180+!!
Brought my water to my friend at the LFS and my nitrAtes were fine at 10. It was my nitrAte kit. It was junk!! New kit an my nitrAtes are always .05 or 10 maybe 20 sometimes. I never see red anyway in more ways then one lol.
If you can answer those questions we can better help you. Feel free to add all and any information you want.
Thanks,
The Con