Ratio 4x2 with a Shelf and 100w pro heat RHP and Herpstat 2.
Question, wen using a Herpstat 2 with RHP , I am trying to aim for 90F, so I am pretty close I have my herpstat set to 87.3f and I get 89f to 90f Is this Normal? to have to set your Herpstat temp a few degrees lower to get basking spot of 90f?
My basking spot for 90f is the Shelf.
Yes it is normal for the temp of the hotspot and set temp to be different. For example i have one stack with 75 watt pro panels set to 83, the probe is mounted on the wall about 3" below the panel. The hot spot is upper 80s to low 90s.
Another stack has 40 watt rbi panels. Probe is sticking out under the panel about 4" below it. Thermostat is set to 87, hot spot is upper 80s to low 90s.
Another stack has 120 watt panels, probe free hanging about 4" from the panel. Thermostat set to 83. Hot spot upper 80s low 90s.
Each setup requires tweaking and adjusting.
OK cool, and will it hurt my snake if the hotspot is 1 or 2 degrees higher then 90f?
last night I up the temp to 87.5f and all night and this morning its been at 89 to 90f
But I will watch this until next Monday then I will put her in on 4/4/22
A couple degrees warmer won’t hurt them while you’re dialing it in.
In my experience yes. The setting on the stat is a guide and never 100% what you get. I rely on actual temperatures to set my stats.
Edit: I also calibrate my thermometers monthly (As the food industry and health sector have to do) to be sure they are accurate. Process for calibration :- Boiling water is 100 degrees C - Ice water is zero C (google can translate to F). if I don’t get those readings I know my thermometers are out and by how much.
This I have to do to be safe, never hurts.
Question I pick up a Grapvine branch today, from a nursery, But its not sandblasted, is it still safe to use with my ball python?
OK thanks this takes some tension off me, just want to do it right, my ball been in a tub for 8 months since i bought her at 90 grams
I know the feeling, I am here for the same reason, to be sure i am doing things right. Also if my advice is wrong, others here will soon say different and help us both 
Personally, I am a bit paranoid and I would heat or treat the Grapevine branch to be sure no parasites from the nursery. That cover might be hide enough though.
Yes relax, hides are not that critical in a tub if they are eating, happy and have a thermal gradient.
And If you have got her from 90 to 900g you must be doing something right
I got her at last July at 90g and just weight her last week she is 417g.
I rinse it down in the shower with hot water, then I sprayed it down with some Chlorhexidine 2% I mix. Might spray it a couple more times
Not sure if this will help.