Hi Blue!
The Helix DBS 1000 has a maximum output of 500 watts. I don't remember right off-hand what the Flexwatt wattage is per foot for each size tape so you'll have to look that up & see how many racks you can run off of one thermostat.
I believe it's really a matter of preferrence whether you use one unit for multiple racks or one unit per rack. I would look at Spyder Robotics' Herpstat thermostats, too. With the Herpstat II and Herpstat Pro you can run & monitor several racks/cages with one unit.
Some people like having one unit per rack/cage in case a unit malfunctions you don't have all of your eggs in one basket (so to speak). As far as Helix versus Herpstat - I believe that it's like the ol' Ford vs Chevy debate. I use both of them and have no complaints about either one.
I use one of those radiator type of heaters with a thermostat on it for my reptile room heat and let the Helix & Herpstats do their thing for the racks & cages.
Catch ya later!
HH
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Due to political correctness run amuck,
this ol' hillbilly is now referred to as an:
Appalachian American

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