New BP in Tub - Heat problems

[AleriaCarventus]

Hi folks! We are new owners of a tiny little ball python. We purchased a full size enclosure for her but the breeder recommended we start her off in a series of tubs as she grows. We are having some trouble getting ambient temperatures up to recommended temps. The cool side is sitting at 75F and the hot side ambient is around 78-80, though a temp gun reading of the substrate indicates around 84F.
Details:

Plastic tub with heat tape covering 1/3 hooked to thermostat. Thermostat is set at 90 but I am afraid if that is too warm? Too cold? I worry about her burrowing and getting burnt.
Substrate is coconut husk, and she has a small water dish on the cold side, and a hide on the warm side. I know that ideally you would have two hides but it's almost too small as is. We will probably pick up a slightly larger tub and a second hide soon.

My question - what should the thermostat be at, roughly? How high is too high?
Are we looking at needing a second heat source at this point, such as a heat lamp/bulb ?

Lastly I apologize if I am not making any sense as I haven't slept in 33 hours. Thank you in advance for your help! We have done a lot of research but are very nervous about making things right for our little bloop.

[bcr229]

Move all but a think layer of substrate from the tub floor over the heat tape area and put a hide over it. That will make a nice warm area for your snake. The rest of the tub will be fine as is.

[AleriaCarventus]

Okay, that sounds good. Will the heat tape be okay with the thermostat set around 90?

[PitOnTheProwl]

The inside floor temperature is what you want to monitor.

[Bmocken]

Okay, that sounds good. Will the heat tape be okay with the thermostat set around 90?

With my tub I'm using a uth and my thermometer is set to 95 in order to get my internal floor temp between 88-91 degrees.