The Trade-Air is a variable fan speed controller that alters the speed of your fan to maintain a model temperature in your grow room. You set the temperature you want to maintain with the dial on the front of the unit and then the trade-air switches the speed of your fan depending on if it is getting to hot or cold.
The Primair is an advanced fan speed controller that is capable of adjusting the speed of both intake and outtake fans. An external temperature probe takes readings and the primair unit adjusts the speed of your fans to maintain the room temperature.
Min-max digital thermometers are a great way to keep track of temperature in your hydroponic gardening. This model features a probe to monitor the temperature of your nutrient water as well.
Digital hygrometers take min-max readings on both temperature and humidity in your hydroponic garden. Also features a temperature alarm feature. Batteries included.
No frills min-max thermometer. These units include a simple mechanism for viewing minimum and maximum temperatures. Highest and lower temperatures are recorded by marker indices which are set by the movements of the two mercury thermometers.