First time herp keeper here, I've worked with snakes for about three years now but this is my first time caring for one 24/7. I adopted a ball python about three weeks ago, and I've got him in a modified storage tub with a locking lid and a metal tank screen glued to about half of it, to allow for circulation and so the heat lamp doesn't damage the plastic.

Maintaining temperature and humidity has been mostly trial and error, with a 75 watt day lamp (which I might be downgrading slightly soon, because I switched him from the half log he came with to a set of plastic enclosed hides, and the heat is moving a lot quicker through plastic than wood) and a 40 watt night lamp combined with a bottom heat pad during the night. I've got an infrared thermometer ($25 on amazon, its great) and this setup looks like it's working pretty well, keeping the hot side at 75-90 degrees pretty consistently.

For humidity I moved the humidifier I'd already been using for my own comfort over next to the tub, because the spritzer I had was doing nothing and the heat lamp dried out the coconut fiber substrate I've got him on way too fast. What I'm wondering here is how high is too high with humidity? I know snakes can be prone to respiratory infections, and humidity can increase the likelihood of those, and I'm not sure what I can do to reduce the chances of my snake getting sick. Also, is there anything in my heat setup that's a red flag to anyone more experienced? I've read around online and it seems like I'm doing okay, but it'd be good to have confirmation that there's nothing I'm missing.