If it's just a thermometer you want, no controller, Rainbow Lifegard makes a couple of them... a large one, and a small one. Both have air temp and water temp, and they both keep time also (clock feature). The larger one has an "alert" feature that you can set, and it will sound if the temperature goes outside your designated parameters.
They are considerably more than the Coralife, but considerably less than a controller.
Jenn
They are considerably more than the Coralife, but considerably less than a controller.
Jenn