Cheap and Easy Automatic House Plant Watering System





Introduction: Cheap and Easy Automatic House Plant Watering System

I have plants in my office - the problem is that my days vary wildly and sometimes I forget or don't have time to water the plants. I looked for an automatic house plant watering system and they were very expensive ($49-$100) and I couldn't be sure of the quality.

I was walking in Wal*Mart one evening and went past the pet asile. I picked up some inexpensive aquarium supplies with the intent of putting together my plant watering system. I also went to the hardware asile and picked up a 24 hour light timer. In the end I had to go to a pet specalist store to get the valves that I needed to get it to work.

Here is my supply list
25' Airline Tubing ($2)
4 Gallon Bucket ($2)
Aquarium air pump ($10) - I got a dual line mode, beefier the better (not pictured in the instructable)
24 hour timer ($4) - Originally I used a 1 hour timer, but I found a 30 minute timer that worked better
Lee's Airline Control Kit ($4) - Cat no. 14103 - This is the perfect set for this project - it contains 4 Tee junctions and 5 valves. The valves are inline and all plastic.
Check Valve (Free) - This should come with your pump and is very important for safety (not shown in pictures)

Step 1: Prepare the Junction and Valve

You may have a different step if you are using a different type of valve and/or junction. The nice thing about the Lee's product is that it is modular. First, take the valve and inspect it - the valve is in three parts, the screw adjuster, the valve body and then another little connector. Pull the connector out - I used my teeth :)

Then take the tee junction and press the valve body on to the perpendicular part of the tee.

If you have a different type of junction or inline vavle you made need to fashion a small length of hose to join the tee and the valve - it'll work just fine.

Step 2: Attaching the Pump and Line

Take the assembly from the previous step and attach it to a length of airline tubing. Make the tubing enough to reach from the pump to the bottom of the bucket.

IMPORTANT: Even though it is not pictured, install a check valve close to the pump. This is a important safety point, considering that you are dealing with water and electricty - they don't mix very well!

Step 3: Run the Line to Your Plant

Attach the airline to the assembly and run the line to your plant. You may want to attach it to the bucket with duct tape or some other water proof method.

Try and keep the line from the bucket to the plant as short as possible - dips in the line between the bucket and the plant will reduce the efficently.

Step 4: Connect the Pump to the Timer

Set your timer and connect pump to the electricty.

Step 5: Finishing Up

Fill the bucket with water, it is important to fill it up as much as possible - the efficiency goes down with the water level. Turn on the pump and adjust the valve.

The valve works on suction, as the air rushes by in the tee fitting it will suck water from the valve and that water will be pushed along through the outgoing line to your plant. When it is on it sounds like a coffee pot brewing.

Adjusting the valve can be tricky - if the valve is open too much air will just escape and make bubbles in the bucket, but you want to get enough water to your plant. Mine are adjusted down pretty far - after all 30 minutes of a drop of water a second is actually quite a bit of water. I "calibrated" mine with a measuring cup.

Maintaining the system is minimal, just keep the water above the 1/2 line and you'll be okay. Also, keep things from floating around in the bucket. Check the lines to your plants every once in a while, the water can come out with a surprising amount of force - I found when my bucket will totally full the line would spit water over the edge of the pot.

Note: The photographs in this instructable were setup - the one in my office actually follows all the steps :)



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    42 Discussions

    Hi! Seems the water doesn't go through the tube.. even with this kit.

    Can you help?


    Hi! I'm wondering, watering plant once a week?... do you feed the plant when it's dry all the time?

    thank you!

    i would just use one of these auto plant waters. NO ELECTRICITY needed. And it is cheap and simple.

    I would use this to water your plant automatically when you are on vacation.

    if the water sorce can be lifted above the pant pots then you dont need pump the gravity will do it and drip or flow can be regulatet by the nozzle size.
    I would use it to water my button mushrooms but they need to be sprayed.

    I'm trying this method but I'm finding that after about 5 minutes bubbles stop climbing to the end of the tube and all I get is air and some water drops clinging to the inside of the tube.
    Not sure if I need more water or more air power.

    1 reply

    I am gonna say more air is the issue. I have a whisper 10 and all I get is exactly what you described. I am thinking great air pressure will cause a faster stream thus sucking in more water.

    OMG!!!! I have been waitin a week to build this and the airline kit arrived today and it's the WRONG ONE!!!! Let me rephase that, it's the right kit, 14103 but it's not the one you used in your instructions. My Air valve does not allow me remove the end tip to insert the T. I made a crude version and it just barely sucked up anything. Frustrated!!!!!!! Can you recomend somewhere that still sells the one you used?

    I came up with one you can build yourself for 20 cents (or less) and it is made largely from materials you already have in your home (i.e. plastic soda bottles.) For more information on that go to w w w dot kahnlandscaping dot com. The how-to link is right on the main page.


    A low tech solution to the problem is Water Worm Works for all kinds of plants and won't over-water.

    The AquaPad is also a great solution...

     So one airtube from the pump to the bucket then another airtube from the t-joint to the plant?

    1 reply

    A simple, reliable, one pump and one timer, automatic watering system can be constructed with the items already mentioned above. The 1-minute interval timer sold by Harbor Freight Tools will allow a minimum on-off cycle of one minute. The 66 gph pump sold by Harbor Freight Tools has a grey, sliding, intake regulator/valve which can be positioned to reduce the pump output. With the regulator valve at full open, the pump expells 1.1 gallons of fluid per minute. At the minimal pump regulator valve setting, it pumps 3 cups of fluid per minute. For a single plant set-up, you would use the minimal pump regulator setting. If 3 cups of fluid is still too much fluid, you can reduce the output as follows: Insert a plastic 1/4" T-valve (T) in the pump output line at least an inch or more above the tank water-line. This will split the minimal setting output into two, 1 1/2 cup per minute streams. Cut and attach a short 1 1/2 inch section of 1/4" hose to each end of the T-valve. Next, position a screw-top, plastic air control valve (CV) to the free end of each of these hose sections. Your assembly will look like this ---CV---T---CV---. You can now manipulate the flow through each control valve. With one valve almost totally open and the other almost totally closed, you can limit the slowest flow to about 3/4 cup per minute. (Most any plant pot can handle this amount of water inflowing over a 1 minute time period.) Connect this slowest flow output via the appropriate plastic tube to the plant container. The maximum flow stream is then positioned so that it spills back into your reservoir. A bit of trial and error manipulation of the control-valves (CV) will provide you with the amount of water that you want your plant to receive. The rest of the output goes back into the tank and is conserved for use during future watering cycles. There are only two caveats that you must keep in mind and address. One is that the maximum flow output spout going back into the reservoir must NOT be positioned below the water-line of the reservoir. If it is, a siphoning connection will be created from the reservoir to the plant thus emptying the reservoir onto the plant while the timer is off. The second caveat is that you should keep the flow distribution assembly positioned over the reservoir. A suction cup holder or a binder clip can provide support for this positioning. This positioning is needed because the control-valves (CV) will emit an occasional drop of water out of the top stem. These drops will fall harmlessly back into the tank if you keep the assembly over the reservoir. You can expand this set-up to water multiple plants by the addition of a series of in-line control valves (CV) and the proper manipulation of the pump intake regulator, the control-valve outputs, and the timer on-off times. If you want to keep the amount of water sent to multiple plants equal, you must shoot for approximately equal tube lengths to each plant. Moreover, you must assure that the discharge port of each tube at the plants is of an equal height above the floor. Use plastic or bamboo stakes for this height adjustment. Unequal discharge positions and/or tube lengths will unbalance the equal flow pattern. With a minimum of trial and error this system works very well with one timer, one pump, and one reservoir for single and multiple plant set-ups. It can be constructed from off-the shelf, retail components for less than $30 total. Most of the components go on sale from time to time for even greater economy. (Note: An alternate 11-piece TOP FIN air-flow connection kit is available at Pet Smart for $3.50. It contains 5 air control valves (CV), 4 T-valves (T), and 2 suction cups.) Lastly, liquid plant fertilizer can be added to this system if you take precautions to prevent algae growth that can clog the pump. This algae growth prevention can be accomplished by enclosing your tank in a black plastic bag or surrounding it with aluminum foil. No light, no algae. My thanks go out to all who worked on this project. My improvements are simply extensions of the excellent work already presented by previous contributors.

    I thought about this at first but the problem is that they work too well! That particular pump is 145 Gal/hour - that means in a half hour (the smallest setting most inexpensive household timers can do) you would pump 72 gallons in the half an hour way, way, way too much. I looked for a pump that did something like a 1 gal/hour but I couldn't easily find one.

    I found a submersible pump at Harbor Freight for $5 that does 66gpm, as well as a digital timer for $8 that looks like it has a 1 minute granularity. If that's still too much, you could have 2 timers in series for a 1 second granularity. You could also reduce the gpm volume by using a bypass line.

    Great find! I wish I had a habor freight store in my town. Couple of notes - I notice that this model only has a 16" lift - you may need a wide short reservoir and it may limit your hose/line setup. I willing to bet you could use a irrigation manifold (neat, but wrong size line for my setup) to split it up - although you wouldn't be able to adjust each line's flow. I look forward to see how your setup works - write an instructable and share!

    Just a quick note. Both those pumps are magnetically coupled which means you can readily throttle the output with a valve without damaging the pump. Don't throttle the input as you will cause cavitation issues. So, while the max is 145 GPH, you can dial it down to almost nothing.