This design is part of my Plant Grow Tent Project:
https://www.thingiverse.com/thing:6724085

This is my DIY Automated Watering System for indoor grow tents.
Teaser: https://youtube.com/shorts/qljEUIXielk
https://youtube.com/shorts/QoOwFM8aUhE

Valuable Comments and a Make:
https://www.printables.com/de/model/894984-461-auto-watering-for-grow-tent/comments

Here will you find the .pdf handout:
https://drive.google.com/drive/u/1/folders/1B2OIvdmnxRqS1MRcuJaII8CSyUZvPqu5

Complete Build Tutorial:
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Features:

• 12V Safe Power System: Runs on a simple 12-volt system, making it safe and easy to use at home.
• Easy-to-Build: Most components are 3D printable and straightforward to source, so you can customize the setup as you like.
• Smart Humidity Sensing: The system includes a sensor that checks the soil's moisture levels. When the humidity drops below your preset target, the pump kicks in to hydrate the plants.
• Water Flow Control: Integrated voltage regulator lets you adjust the pump’s water flow. A small digital display shows the voltage, making it easy to manage your watering strategy.
• Large External Water Tank: Place the tank outside the tent to avoid light exposure and prevent algae growth. Choose any size tank to extend watering intervals, perfect for vacations.
• Flexible Setup: The controller can be mounted or hung for easy adjustments and plant changes. The electronics are designed to stay above the water level to prevent any electrical issues.
• Essential Tips: Don’t forget to add good ventilation, especially when the lights are off to prevent condensation. Insulate your tent from the ground to keep the environment stable. Need more air circulation? Just add more fans—they're cheap and easy to install.

This is my universal Enviroment Controller:
https://www.thingiverse.com/thing:5470216

These are the Products I used for the Watering System:

12V Micro DC Water Pump Food Grade Water Dispenser 370 Mini Pump 12 volt 0.7-1.2L/min Low Noise Long Life Self-priming Pump
https://de.aliexpress.com/item/1005002863109224.html

Black Lawn Hose Garden Watering 1/4" PVC Hose Micro Drip for Irrigation Pipe Tubing Lawn Balcony Plants Flower Pipes
https://www.aliexpress.com/item/1005005993039837.html

LM2596 DC DC Step Down Converter Voltage Regulator LED Display Voltmeter 4.0~40 to 1.3-37V Buck Adapter Adjustable Power Supply
https://www.aliexpress.com/item/1005002850012207.html

XH-M214 12V Soil Humidity Sensor Controller Irrigation System Automatic Watering Module Digital Display
https://www.aliexpress.com/item/1005005235741593.html

Happy Growing!

2024-06-02: FAQ: How many of these units can I power up with a 60 W power supply?

It depends, of course, on the power used by your pump. If you run it at full 12 V, you'll have higher power usage due to the higher water flow. If you run it at 5 V, the power usage will be much lower. It also depends on where your water reservoir is located. If it hangs above your plant, your pump won't need much power. If your reservoir is 2m below your tent, then it will need much more. Here are the values if your water reservoir is on the same floor as your tent:

Humidity Measurement: 0.5 W
Low 5 V Pump Speed: 2.5 W
High 12 V Pump Speed: 5 W

For more details, check out the short video I made for you.
 https://youtube.com/shorts/JPaF6BR6A5s

Since not all pumps will run simultaneously and you can set them up one by one, you can set up a lot! If you want all of them to be able to run at full speed, then I would say 10 units.

Update: FMEA - 2024-06-14
!!! I strongly recommend the use of the water diffuser because if water is added punctually, it might just run through the pot and since the humidity levels of the sensor will not rise, the pump might empty your tank into your tent! !!!
https://youtube.com/shorts/VIaMHDGybTU

Water Dripping System:
https://youtube.com/shorts/K6KnHchQDJc

• Provides area-wide consistent moisture levels.
• Easy to level for harmonic water distribution.
• Covers the diameter Ø 160 mm.
• Dripping holes can be easily modified by drilling.
• Easily integrates with timers and sensors.

Update: FMEA - 2024-06-15
It's possible that the water tank could be emptied by the pump because if the floating switch or the moisture sensor fails to close, the controller will keep the pump running. The system won't know that the tank is empty. This could happen when you are away, and the person who should refill the water doesn't do their job, or you have a sensor malfunction, or something else unexpected occurs. To avoid taking chances, you can use a time relay that will disable the pump after a certain amount of time. Another approach is to just let the pump run continuously. To assess the risk involved in having the pump running 24/7, I conducted a small experiment. I placed the pump on a wooden piece and let it run. I let it run for about 5 days, unplugging it whenever I was not home, so this is not a true 24/7 test. But for the time it was running and pumping air, it did not heat up, and the plastic components also did not show any signs of degradation. I used the pump afterwards, and it still worked as usual. As with everything you learn from the internet—do your own research. For me, the test was significant enough to trust the pump.
https://youtube.com/shorts/myiQaPzl6Kw

Update: 2024-06-24 Added a Closed Dripper
https://youtube.com/shorts/e-XAAQLbf8I

• This design provides even better water distribution, relying on the pressure generated by the pump rather than gravity due to water buildup inside the ring.
• Printable without support structures thanks to the 45° angles.
• It is not possible to manually clean inside the ring. However, it can be rinsed with higher pressure. Normally, if only water is used, nothing should happen. Holes can be cleaned from the outside.
• Requires more material to print.

2024-07-02: Grow photos added
Since this was a test plant, I did not trim or fertilize it.I just used plain outdoor earth.
I would advise using a mix of automatic watering and manual watering with fertilizer.

Update: 2024-07-07 – Added a Small WaterRing

https://youtube.com/shorts/QoOwFM8aUhE

As requested by a fellow grower, I designed a smaller WaterRing for smaller plants and smaller pots.
WaterRing Tall: Ø160mm
WaterRing Small: Ø100mm

Update: 2024-07-21 – Added a PUSH Modification
I added a modification that uses a different controller. I integrated a water level controller instead of relying on the soil humidity. That means water is pushed via a timer at a defined time through the watering ring onto the soil of the plant. Since the watering ring disperses the water, it will drip and be partly absorbed. When water finally drips through the pot and runs out under it, the water will reach the water level sensor. As soon as this happens, the pump is turned off. This way, the plant will be watered more like the ordinary way. In the garden, I also just water the plants until the water runs through.

I feel the push approach is more simplistic. One does not need to bother where to place the sensor, and one can also use one big drip tray for several plants and thus just use one watering system. You find the design here: https://www.thingiverse.com/thing:6704329

Update: 2024-09-19: Video of the setupand my first mature plant
https://www.youtube.com/shorts/Y9EeyDOD0IM

Happy Growing!