I have a baby Hermann's, although he's not so little anymore, almost a yearling now. I wouldn't use the ESU bulb; it's new on the market, and even though they claim it has UVB, I don't think it's been tested out in the real world enough. I've been trying to look into them myself, but haven't found any info. from people are using them. I've used both Reptisun 5.0 and mercury vapor bulbs, and I like the results of the MV bulbs much better, although they are delicate and can blow quickly, which is a real pain. Right now I'm trying a 60w MV bulb with external ballast, which are supposed to be less sensitive.
You would need to use an additional heat source with either a Reptisun or a 60w MV. I use a regular household 100w flood light on a dimmer switch (probably equal to about a 40w flood, but I just happened to have the 100w, so that's what I use). You could also use a ceramic heat emitter on a thermostat.
As much as possible, tortoises should be outside. I have an outdoor pen, and my Hermann's is outside at least part of the day from about mid-March to mid-October, depending on how warm a day it is.
Hope this helps!
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Sohni
Northern California
0.1 Baja de L.A. Rosy Boa
0.1 Okeetee Corn Snake
1.1 Rubber Boas
1.0 Leopard Gecko
0.0.2 Hermann's Tortoises
plus my kids' herps:
0.0.1 California King Snake
1.0 Mexican Rosy Boa
0.1 Leopard Gecko