There are books, pamphlets, and articles on the web to teach anyone - anyone - how to cultivate crops in a hydroponic garden. I have adequate eyesight. I have adequate reading comprehension. I have life experience to apply.
One of the things the resources say is to mind the temperatures. The temperature of the room - air temperature - and the temperature of the hydroponics units - water temperature. I have room heaters and an air conditioner. I can adjust the air temperature and I do, routinely.
It all reads in Fahrenheit unless I touch a button on the back. In any case, 73 is a good compromise between the needs of the farmer (me), the needs of the peppers and tomatoes (warmer), and the needs of the herbs and salad greens (cooler). I've been sort of assuming that the units will align to room temperature. None are in direct sunlight, after all. But all of them are subject to the ultraviolet components of the lights on the unit. That's not a lot of heat, and the ones with fans are getting a little convection cooling, but then there are the pumps.
I knew this. I was a mechanical technician and trained in Nuclear Power. Pumps add heat to a system. In fact, before they ever start pulling control rods to make a reactor deliver power, they heat the system using Main Coolant Pumps in fast speed, all the way to operating temperature. The QYO, iDOO and AeroGarden units all have pumps. So, how do I check their temperatures? It turns out that I have a remote reading temperature detector.
I bought this when the pandemic started. I have a contact thermometer, and an oral thermometer (but don't ask me where that is). Checking the water temperature was a simple matter. Open fill port. Point and shoot. Change the setting from "body" to "surface"
Initial reading of the Harvest was over 80°F. I added three ice cubes and checked after a bit. The photo wouldn't show the reading, so I edited it (shown at left.) Water temperature still exceeds room temperature, so I added more ice.
To make matters simpler, I confirmed that water temperature matches the skin temperature of the unit, and confirmed that with the other units. The bucket was the same temperature without ice that the Harvest was after ice.
There are other reasons than the preferences of the plants for keeping water temperature under control, including algae and bacteria. Thus endeth the lesson.
A quick trip to Amazon and entering non contact infrared thermometer (which is the name on the side of the device above) revealed this bad boy. Unlike the one above, best employed taking human temperatures, this one is general purpose. It can take oven temperatures, wall temperatures, and for my purposes, water temperatures. It will be delivered tomorrow before 22:00.