I think I may have enough heat. When I was using the Zilla Controller, my temps were fluctuating between 84-94, so I know it's gotten hot enough in the past; that's what makes me think this is more of a thermostat than flexwatt problem. I just didn't want the temps fluctuating 10 degrees, so I opted for a better thermostat. That's what makes me think there's enough heat (because it has reached 90 and above before), but the Herpstat's reading is only 77-78 (and as I look at it now, it has dropped to 76.8), and therefore the tubs are only ~77 (tubs are all being monitored separately by different thermometers). Still has the red light on like it's trying to heat at full power, but the temps are going down instead of up . . .