High Nitrate Levels

[lil fish]

I read RTR's article on nitrification, but I still have a question. I had a fish die (possibly chemical balance, but possibly old age) so I did a water test using API's Freshwater master test kit. I found that I had a slightly elevated pH (8.1, it usually runs 7., and a very elevated nitrate (40-80). I tested the tap water it was 0ppm for nitrate.

What I put in my water:
Seachem Prime
Seachem Flourish:Iron (no phospates or nitrates) (Ive used this for about 2 weeks when my Wisteria started to lose its leaves)
weekly/biweekly water changes (1/4-1/5).

Is my best bet on reducing the nitrate levels, to get another wisteria plant?

[jmiller]

Larger water changes will do it.

[Pufferpunk]

+1, should be ding 50% & more, if it's >20ppm.