Time to Water the Christmas Tree

Every year we have a Christmas tree and every year someone gets the fun job of watering it. One must crawl under the branches dragging a small pot to add water to the tree stand. And do it just about every day. So I decided to build an auxiliary water tank to do the job automatically.

Arduino nano

DC 12V Relay Module 2 Channel

Fish tank float switch

Horizontal float switch

13gal Water Storage Container

12vdc Water pump

12vdc LED light

led light (optional)

1 foot of 1/2 pvc tubing

2" x 4" x 1/8" plexiglass

4" x 4" project box

20' wire

clear flexible tubing

I like to begin my Arduino projects by mocking up the wiring using bread boards and jumper wires. Adding each component one by one, ensuring that I have hooked them up correctly and they are giving the expected results. So follow the above diagram to construct the device.

Once actioning the float switches turn the relays on and off thus turning the LED lights on and off. You are ready to build your automated tree watering station.

Measure the diameter of the horizontal float switch and drill the appropriate size hole in the side of the water tank. Be sure not to drill it too low or the float switch will not open completely, which is important to signal that the water tank is low.

Next, use a small piece of plexiglass to make a mount for the fish tank float. A heat gun is very useful to bend plexi. Otherwise, it can be cut and glued into a custom mount that will fit in your Christmas tree stand.

You will notice that all the devices (ie the pump, LED lamp) are 12vdc. I like to use low voltage especially around water. Using the schematic, wire the float switches to the Arduino and the LED light and pump into the relays.

I like to use wire/panel connectors and barrel connectors to make my projects easy to disassemble. Especially this one as it is only in use 1 month out of the year.

But wire it as seems best to you and be careful of polarity as DC voltage devices don't like to be reversed.

The water tank was very nice and came with a valve, quick disconnect, tubing and clamps. A great kit for this project. Starting from the water tank run tubing to the 12vdc pump. From the pump, run tubing to the tree. Its very important that you do not just stick the tubing into the tree stand water reservoir. Once the pump fills the tree stand, the tubing will pull a vacuum and siphon all the water back into the tank.

To prevent siphoning, zip tie a short piece of PVC pipe to the trunk of the tree and insert the tubing into the top of the pipe - see photo

If you have looked at the Arduino code and tested everything, you will see that in order for the pump to come on the floats will be in opposite states. The horizontal tank float will be closed and the vertical tree stand float will be open. The LED bright light comes on when tree wants water. If the large LED stays on, then the reservoir tank is probably low/empty and needs water.

Merry Christmas