ok, so I am planning on buying the economy rack from animal plastics with belly heat built in and I know I need a proportional thermo, but its a 6 tub rack. does that mean I need 6 thermostats? or would I be able to rig one of them to take care of all 6 tubs? 600 bucks for the thermostats will kill me haha ill obviously do it but I was just wondering..