Also, water parameters can look "fine" before cycling really begins. When you first put water in, you're probably going to read zero across the board. As the nitrogen fixing bacteria multiply, you should see sequential spikes in Ammonia, Nitrite and then Nitrate. This is why a test kit is important. A normal tank usually takes 3 to 6 weeks to fully cycle. If the axolotl is in the tank during that time, an ammonia spike can damage the gills and cause other issues.