I would not recommend getting it just yet. First determine what the source of the nitrates is. If it was temporary, and due to something like a fish dying, then you should be fine. The key with all nems is stability. If you're nitrate levels are bouncing around, then it means that the tank is not stable. Haddoni could get used to a tank with 15-20ppm nitrate, but of course 0 is the best.