Higher Nitrites?

So I have this tank set up, and it did not cycle properly before the axolotls arrived.

I had tried cycling it with feeder fish which was a mistake. There were 3 in a 55 gallon tank and the last fish died of ich (it was not noticible in the first two). I spiked the tank temperature over 90, and kept it that way a while blah blah blah.

Ich was gone, no big deal there. But the tank was not cycled.

I received my axolotls in the mail yesterday and I had the tank down to a suitable temperature (it was 70 but my fans cooled it down to 66 over the night time).

So before I put the axolotls in my parameters were 6.4 pH, .5 ammonia, 2 Nitrite and 0 Nitrate.

Since the Nitrite and ammonia weren't ideal I decided to make sure to check daily incase I needed to do water changes to fix a level.

Today the readings are 66 for the temperature (my fans seemed to cool it down well over the night time, will continue to do this). 7.6 pH, 0-.25 ammonia (was difficult to discern between the two), 0 nitrate and 2+ nitrite.

So my question is what do I need to do to get the nitrite where it needs to be? I thought originally it was because I had misplaced my water conditioner - prior to the Ich issue. Since the ich issue there were no living things in the tank so I didn't bother with conditioning.

The day before the axolotls arrived I did condition the water and everything with the water change, then they came and I checked everything again. I know it's ideal to be under 1 for that, but I'm not sure how to rectify this.

If it's something that happens when your tank becomes cycled naturally - what is the level that is dangerous? All my other parameters are within safe range so I would like to know is there a range of nitrite that I should absolutely change water on if all the others are ok?

Thanks

Yes you absolutely need to do a huge water change asap. Honestly it was irresponsible to even put the axies in the tank when the nitrite is that high. Ideally nitrite should be at 0 always. But when you're cycling the tank it's not possible to keep it at 0 and still have the bacteria multiply (it's food for them) so you can let it go up to 1 during that time. If it is anything over 0 it will stress your axies so max 1 is where you should ever let it go. 2 might not look like a big number, but it's twice as much as the recommended max level.

Can you elaborate a little on the cause when the other parameters are okay?

The reason I'm asking isn't to dispute what you've said or anything. But I hadn't swapped it at that time is one of the causes I found online was related changing water too much, since I had just swapped water I was worried that another water change would exacerbate the problem by messing up the ammonia level even more, since it's already almost zero.

It's definitely not excessive waste, overcrowding or overfeeding.

Basic nitrogen cycle:
Wastes - > ammonia -> bacteria A "eat" ammonia and produce -> nitrite -> bacteria B "eat" nitrite and produce -> nitrate -> water change to remove nitrate.

Before you put the axies in the tank, the parameters were ammonia 0.5, nitrite 2, and nitrate 0.
So there is an ammonia source in the tank (poop, left over food from the fish etc.) because it was at 0.5. There are not enough of bacteria A to keep the ammonia at 0, which it would be in a cycled tank. But there are enough of bacteria A to convert some of the ammonia and bring the nitrite up to 2. Bacteria B would be needed to convert nitrite to nitrate, but since the nitrate is at 0 and nitrite keeps rising, there aren't any.
Cycling the tank basically means growing enough of the two bacteria in there to keep the water parameters safe: ammonia 0, nitrite 0, and a reading of nitrates. Until the cycle is ready you need to do daily water changes to keep the water parameters at safe levels. Ammonia and nitrite are toxic so they need to stay under 1 at all times (meaning they can be max 1 right before the water change). Nitrate is less toxic, but can be harmful in higher concentrations so it should be kept under 40 by weekly water changes.

If one of those parameters is off, the best way to quickly correct it is to do a water change. I know some fish keepers don't do that, but axolotls require good water parameters at all times.

I had ended up doing a 50% change and it had lowered the ammonia and nitrate by half, but the Nitrite only lowered a little so I guess I'll end up doing another 50% today and see how it goes.

Thanks for the response