• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

I found a use for surplus tubes

We just setup a 3 season room and brought in all our plants. While looking for a heating sources for the plants, cam across a few concepts. One concept was a dish looking thing that the pots sit on. Since we are calling them plant heaters, they are pricy.

So I thought about using low wattage aquarium heaters. But even a 50 watt one after shipping costs gets pricy. I need about 20 of them.

Then it hit me. Why not use the surplus vacum tubes I have. I could put one or more in each pot depending on the pot size. I have a few 12V power supplies (a 10 amp one and a 75 amp one). All I need to do is put it on a timer, and have it come on early morning, evening, and nite. The room does pretty good in the afternoon since it gets a lot of direct sun.