Increase in nitrite level

[kk_fish]

My nitrite level in my planted aquarium has shot up even though there are no fish in my tank. Last week the nitrite reading was 0. The ammonia and nitrate is still 0.

can some please let me know how can this happen and will this be a problem for my plants.
Thanks

[Fishguy2727]

Did you add any fertilizers?
What is the nitrite level?

[kk_fish]

I am using eco-complete plant substrate in my 20 gallon tank and currently my nitrite level is 0.5ppm

[markbob]

It won't hurt the plants, keep an eye on your nitrate level over the next day or to and see if it goes up and the nitrite level goes down.