Help! Ammonia at 0 but Nitrites above 5.0?

[siglingu]

This morning when I checked my tank, ammonia was 0.0ppm and nitrites seemed to be way over 5.0ppm. So I did a water change to get a better reading of the nitrites, and am now seeing this:

What should I do now - re-dose ammonia? Wait for the nitrites to drop further, and then re-dose ammonia?
If it helps, I am 2.5 weeks into cycling. I have been seeing ammonia drop from 1.0 to 0 in ~24 hrs, and added TSS 1 week ago.

Thank you in advance!

 

[Essjay]

Where are you in the cycling method?

If you are at the stage where you have added 3 ppm ammonia and have been testing every third day and have now reached a day where ammonia is under 0.75ppm and nitrite is over 2 ppm, you need to add another 3 ppm dose of ammonia and start testing every other day. The next stage is a bit complicated to explain. You need to do the tests every second day until you have a reading of zero ammonia, then another zero ammonia 2 days later. When you reach that target to add a smaller, 1 ppm dose of ammonia.