Odd Nitrite reading

[Durvish]

I have a cycled, planted 10 gal tank. Half a dozen glass shrimp, some hitch hiking snails and a dwarf gourami. Since last friday I have been reading 0 Nitrites. There has been a steady rise in Ammonia of about .25ppm per day and Nitrates have been holding at 20 to 30ppm. I am doing 20% to 25% pwcs whenever I get a bit over .25ppm Ammonia, but the complete lack of Nitrites is getting a bit funky.

 

[Durvish]

So I went through my notes and this all started when I added carbon to the filter. Would carbon cause a mini-cycle? That's what this looks like, but I didn't change anything else other than adding the ghost shrimp?

 

[hdultra]

IMO I think you increased the bio-load. and possibly going through a mini cycle.

I doubt the carbon had anything to do with it.

Just keep a eye on it.