No need to apologize at all its a learning experience. Ambient is usually controlled by a whole room heater, Radiant heat panel (RHP), heat bulbs, or ceramic heating element (CHE). These are typically also regulated. Typically it is the CHE or Heat bulb. You put this above the tub or tank and have a thermometer in the tub. I have my ambient at about 80F. I have a fully enclosed rack and my home stays at 70 year round so my ambient stays pretty steady.