no matter how hard i search i cant seem to find where anyone puts the probe for the thermostat in a rack. obviously you dont have a t-stat for each tub so how do you know that every tub in a 20 tub rack is at the exact rite temp. im sure this is something everyone knows but im a noob trying to set up my first rack and it is now the only thing irritating me about the whole thing. thnx in advance.