My recommendation would be to claim a faulty nitrite test kit with whoever you bought it off of, and get a replacement (or refund). Then test again once the new kit comes in. I absolutely don't think you can trust the results off of this test. Unless there's an unknown ammonia source that is being consumed, or a source of nitrite itself, you should not get such high nitrite readings. It's just super off.Update:
Tested a 50/50 mix of the new saltwater in the tank with fresh mixed saltwater that reads 0ppm by itself, and the result is a color between 0.5 ppm and 1.0 ppm.
Multiples by 2 this must mean the new tank saltwater is now around 2ppm. Guess this is just a case where the API test kit colors are near impossible to decipher.
What’s the next move here? redose ammonia just a tad? worried about raising nitrite too high again
The recommendation others probably will give would be just to ignore nitrite completely, especially after you've done such a massive water change. Just base cycling results off of your ammonia readings.