Hello all!

I have a question regarding a nitrite spike and my Mississippi map hatchlings. I am still learning about the nitrate cycle. I was unable to fully cycle the tank before adding the turtles.

For the entire month since I received them,I have been testing my levels everyday and nothing has been alarming. Until yesterday, nitrites spiked to 5.0ppm ,ammonia is at 0.25 ppm and nitrates are around 10ppm. I have done a 50% water change and a few hours later I am getting the same reading.

I have done some water changes in the past month and have rinsed the filter (with tank water). Running Fluval 307 in a half filled 40 gallon breeder

I do feed them in the tank but that stops today lol.

I am wondering how harmful these levels are and what can be done to lower them immediately. I do also understand that it may be just the cycle but I’m quite confused.

Any info is helpful!