Introduction: Automatic Plant Watering Device (simple Version)

This Instructable will teach you how to simply make an automatic plant water-er. Perfect for when you're going on vacation or when you just don't remember to water your plants. It will provide a specific dose of water on whatever schedule you set to one plant.

I made this to keep my pot of dragon trees tree alive while I was out of town for 5 weeks. It's a bunch of big trees in a small pot so they need to be watered pretty often and I didn't feel like calling in friend favors to stop by every other day for more than a month. Those gel packs, plastic bags, 2 liter bottles, plant wicks, etc wouldn't work because they don't hold or move enough water. (The tree goes through about a cup and a half of water a day.) And commercial timed pumps things were expensive. It worked so well I've kept using it even when I'm not on vacation. It's been working perfectly every day for two years. As long as I remember to fill it up once a month.

It's not the cheapest solution, but it's a lot cheaper than the commercial versions I found (and those even looked a little cheap to me). Some would have required me to have a running hose in my house for the whole time I was on vacation, which sounds like an invitation to a flooded house to me. This one costs much less (You can do it for less than $30 depending on what parts you have lying around and how much you bargain hunt) and is an easy afternoon project.

It's very simple to make: The most complex part is programing the vacation timers.

It's reliable: It always delivers the exact same amount of water, and there's no chance of flooding your house while on vacation.


  • 1 five gallon plastic bucket (or some other reservoir for water like a plastic garbage can.)
  • 1 smaller, plastic tub. (Like those disposable tubs for leftovers, or an old Cool-whip container, etc.)
  • 2 Vacation timers. ($12 each) Important:They must be able to be able to turn on for only one minute, which means you can't get the cheapest ones that go by the hour.
  • 2 small submersible pumps like the ones used in small fountains. ($7-$15 each) I used these (if still available) Theseare a good substitute. Or just Google "small fountain pump"
  • Several feet of vinyl tubing. ($1 a foot) (Make sure it fits the outlet of your pump. Mine was 1/4" inner diameter)
  • Several medium size binder clips. (Can substitute hot glue if you don't ever want to reuse any of the parts of this project.)
  • Ground fault interrupter (Recommended, though not required. But it's always a good idea when water and household current are this close together.) ($15-$30)


  • Craft knife.
  • Magic marker.
And if you're like me: first aid kit, fire extinguisher, poison control phone number,acid burn shower, etc.


About 30 minutes (or more if your vacation timers have weird cryptic instructions.)

Step 1: Overview

Cheap pumps and timers aren't particularly accurate. Running one pump for a precise time gave me drastically different amounts of water, and a to-the-second timer was a bit pricey and a pain to build. Setting up a flow meter attached to a switch was going to be tricky and expensive for such a low volume of water.*

So I made this two pump, two reservoir system that delivers exactly the same amount of water every time no mater how inaccurate the pumps and timers are.

The pumps are on two separate timers and run at two different times, one in the main reservoir pumps water into the top one. When it runs for too long and the excess water simply pours back into the bucket. When that one is complete the top pump pumps the container dry, which makes sure that you get exactly the same amount of water every time. No worry about over or under watering.

Lets get started!

  • Though now that I think about it, maybe a pressure switch and a balance might work.... hmm. Next time.

Step 2: Calibrate

First be sure that you have all of the parts and tools listed in the intro.

Next we need to figure out how much water you want to give your plant. To do that...

1) Put one of the pumps in the smaller tub.

Mine had suction cups to secure it.

2 )Put some water in the small tub then pump it out.

Hook up your hose to the outlet and run the pump until it stops pumping anything. This should leave a small amount of water at the bottom that the pump can't reach.

3a) Measure how much water you want your plant to get each time and pour it into the tub.

The volume of the tub now contains the water you measured, the water the pump can't pump, and the pump its self.

3b) Mark the high water level on the tub.

No project is complete without using a Sharpie.

4) Pour the water out and cut a 1" square with the bottom of the hole level with the high water mark.

Only the bottom edge of the hole needs to be precise. This hole is simply so all the extra water pumped in will flow back to the main reservoir.

Step 3: Prepate the Bottom Pump

This pump moves the water from the main reservoir to the measured one we suspend above it.

Place the pump in the bottom of the bucket.

(Or whatever you have. Big plastic water tight vessel. I found my pumps had a hard time pumping more than about 16" vertically, so make sure your pump can actually move water out of whatever you use.

Cut and attach a length of tubing.

This tube will carry the water to the plastic tub on top. It should reach from from the pump outlet to the top of the bucket, plus about 4 inches. You can always cut it long and trim it back. Attach this to the bottom pump.

Step 4: Set Up the Top Pump and Reservoir

Attach the top tub (and pump) to the top edge of the bucket.

I used a couple binder clips which is more than strong enough to support the weight and I know can survive getting a little damp, and have the added advantage of being able to guide the watering tube through the handles.

You could probably also use hot glue if you didn't mind some damage to your bucket and are careful not to melt the tub.

Aim the pipe from the bottom into the top reservoir.

Again the binder clip's handles come in handy for this. But again, hot glue would probably work.

Make sure the top end of the pipe is above the high-water level of the tub. If is in the water there's a small chance that it could start a siphon.

Tip: My pump came with a little right-angle adapter. If you're having trouble getting the water to go in the right direction, and you don't have an adapter you can hot glue the end of the tube shut and cut a hole in the bottom side of the tube.

'Run a length of hose from the top pump.

This one goes to your plant, so how long it needs to be depends on your arrangement

It's not a bad idea to secure the end to the bucket so it doesn't accidentally get pulled out of alignment. Again I used a binder clip.

Step 5: Test It.

Before we finish, let's test it to make sure it works.

Put some water in the bucket and run the bottom pump for a minute.

It should fill, and then overfill the top reservoir with the overflow recycling back into the main bucket. Make sure everything is positioned to minimize splashing, especially splashes that leave the bucket.

Run the top pump for a minute.

The pump should completely pump the water out of the top tub. It will probably run dry for a bit, but it's not much of a problem as long as the pump remains moist. Catch the water it pumps and measure it. It should be roughly equal to what you measured back in step #1.

Calibrate again, if needed.

If you got more water than you wanted then enlarge your hole in the tub. If you didn't get enough then some duct tape over the bottom edge of the hole will fix you up.

Step 6: Set the Timers.

Set up both of the vacation timers.

Follow the instructions that came with your timer. With mine I had to insert a backup battery and set the clock.

Tip: The battery backup on the timers is a good feature if there's a chance of blackouts or brownouts.

Plug each pump into a different vacation timer.

We use two timers because it's important that the pumps run at different times.

Set the timers to turn on on for exactly one minute each, but not at the same time.

For mine the bottom one comes on for one minute from 10:00-10:01 am every day. The top pump from 11:00-11:01 every day. It doesn't matter as long as they don't pump at the same time.

If you don't want it watering every day make sure you can get a timer that will let you set up a weekly schedule.

Step 7: Use!

Put the end of the tube in your pot, plug both of your timers into a handy outlet (or hopefully a GFI plug) and wait for it.

It's not a bad idea to be around the first couple times it goes off just to make 1000% sure that its working right.

Enjoy your vacation/plant negligence!

  • Be sure to refill the bucket every week/month/whatever. (I set up a reminder on my phone.)
  • Every once and a while take it apart and de-gunk it. It gets a little slimy after a few months.
  • I don't know if I'd use it with plant vitamins in the water, I suspect it foul up the pumps pretty fast, though I'd be happy to be proven wrong.

Improvements to make:
  • Some kind of cover to keep bugs and pets out. I don't have bugs or pets where I live.
  • Use a micro controller to control the pumps for more precision than vacation timers.
  • Hook it up to a water sensor in the pot so it only waters when it needs it.
  • Hook a float to a switch in the top reservoir so the bottom pump only runs as long as it needs to.
  • A flow regulator and splitter to water more than one plant at a time. (Just splitting the hose won't work well because the water will just go out the lowest hole.)


JoeW46 made it!(author)2015-10-31

I really like this idea, and I think this is the way to go if your plants require the exact same amount of water each cycle, and if your plants are physically located above the watering system.

On the other hand if you can arrange things so the watering system is above your plants and you can live with a little bit of leeway in how much water they get, I believe you could get by with one timer and one pump with the following mods.

1) Replace the top tupperware dish with a funnel that will hold at least as much water as your plant is going to need. Use hot melt glue to attach a piece to tubing to the bottom of the funnel. Also, you will need to make a frame (Stainless TIG welding rods if you want to be fancy, or coat hangers if you want to do it on the cheep) to suspend the funnel over the bucket or cut a tight fitting hole in the side of the bucket and pass the hose from the bottom of the funnel out through that hole, and seal the hole with aquarium sealant or hot melt glue.. It needs to go downhill the entire run to the plant.

3) Drill a series of holes at the water level around the perimeter of the funnel that corresponds to how much water your plant wants or needs. This is just like the original. Like the original, the bottom of the hole(s) will represent the level. Note in this case that we want to ensure that any excess water will want to drain out of the funnel as quickly as possibly. This is more important in this case to ensure the plant gets a near constant dose of water.

4) Put the pump in the bottom of the the large bucket and run a piece of tubing up to the top of the funnel and set it so the water drips down one side of the funnel where there are no holes. The idea is to not have the water splunk right down to the bottom.

5) The system *may* work reasonably OK at this point. The pump should fill the funnel up much faster than the funnel will drain into the plant. The plant will get a bit more water than the height of the funnel. You can file the overflow holes in the funnel a bit bigger if the excess water going to the plant is too much.

6) If you want even better control, you can put a restriction in line with the plant. And aquarium air valve or tubing clamp would work. The more you slow down the flow of water to the plant, the closer the amount of water metered out into the funnel will match the amount of water the plant will get. The plant will still get the dose of water, it will just take it longer for it to get to the plant.

If you can set things up so the water is higher than the plant you can cut the cost of the project near in half by getting rid of one pump and one timer. The genius was still in the original idea of gross pumping into a container that will act as a metering gauge. And the origional idea with two pumps will be more accurate.

asgarbs made it!(author)2015-04-13


The+Freak made it!(author)2014-06-17

Ah genius stuff. I happen to have some digital timers which can run for a minute and some non digital which can run for a minimum of 15 minutes, but I didn't find an easy way to give the same amount (mostly not to much) every single time. This is so simple en therefore so brilliant! Love it!

LimeEgypt made it!(author)2012-12-05

Thanks for sharing your design. After five years of operation, do you have any improvements or tips to share? Have both pumps lasted? Any floods?

Grathio made it!(author)2012-12-06

Still runs perfectly every day. Since it holds straight tap water the whole thing needs to be taken apart and cleaned every few months. Chlorinating the water would take care of that, but it's bad for plants. It only takes about 15 minutes every few months so it's not a big deal.

tulip8 made it!(author)2011-08-12

Cool idea on the pump, and could be really useful for certain plants/gardens. But, there is a cheaper and easier option - have you heard of HydroSpike? It is a ceramic spike that uses capillary action. I think it is designed to drip when your plant needs based on soil dryness. And it's less than $5 a spike on Amazon. here's the website:

Grathio made it!(author)2011-08-13

And if $5 is too expensive you can make your own for nearly free by drilling a couple holes in the lid of a soda or water bottle, fill it with water, and invert it into the pot with about 1/4 of it under the soil.

The advantage of my system is that it can hold gallons of water and can water even the largest and most expensive plant for weeks. The drip and capillary action ones you mention hold only a few ounces at most. My dragon tree goes through more water than that in an afternoon.

tulip8 made it!(author)2011-08-13

If $5 is too much, then your free idea sounds like it may be the way to go. One thing to note is that hydrospike can be hooked up to as big of a water container as you want, there is no limit. You could hook it up to a bathtub of water if you wanted to, since you pick whatever water container you want and you move the plant wherever you want. It's pretty cool.

YotaTruck made it!(author)2010-04-26

What a great idea! So simple it just works. The top pump running dry seems like the only possible hiccup, but @ $10 I guess the remote possibility of a burned out pump is no biggie except for the plant dying.

Grathio made it!(author)2010-04-27

I was concerned about wearing out the pump early on, but I've been running it every day for three years now and it still works perfectly.  Which is frankly a lot more than I expected from a $10 pump.

Next time I'm digging around behind my plant I'll probably switch the pumps so that they wear more evenly and hopefully I can get another 3 years out of it.

rube_goldberg made it!(author)2009-11-18

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.

Grathio made it!(author)2009-11-20

 This is a great comment and would make a great Instructable.  Hate to see all of your hard work and thought languishing down here in the comments of an unpopular Instructable when it could the the feature of its own!

CyberBlade made it!(author)2009-11-09

Sweet idea! I have only one question. When the water in the smaller tank runs out and the pump starts running dry, won't this shorten the life of the pump?

Grathio made it!(author)2009-11-09

Yes, it probably does shorten the life of the pump a bit.  But if you use a timer that has minute resolution it will only run empty for a short time.  More like running damp than running dry.

Mine has been running daily for two and a half years and so far hasn't failed me yet...

JoeInventor2 made it!(author)2009-11-08

Even tho this is genius in nature, it goes beyond simplicity in nature.
Try this:
Pick-up a 45 gallon plastic solution container from any local car wash. free
Pick-up a aquairium POWER HEAD. $20.00's
Pick-up a 110v appliance timer  $8-15.00's
25', 50' or whatever length of 1/4" air line tubing. $5-12.00's
1, 3-4-5-6 way gange valve from pet supply. $5-9,00's

Silicone the power-head flow-port closed and leave air-line port open for airline tubing.
Attatch powerhead to bottom inside of container.
Thread tubing (water-tight seal)  from powerhead thru container-wall and attatch to gange valve.
Thread power-head cord thru top of container and plug into appliance timer, don't forget to set times for irrigation on timer after trial and error due to individual container watering needs. Adjust gange valve to achieve best results...
(NOTE:) Your main solution container can be placed outdoors to collect nutrient fresh rainwater from gutter-downspout by cutting a opening on the side of collection container/reservoir then add your wifes nylon anklet to end for filtering of debris, run tubing thru house wall, to gange valve and finally to plant ccontainers.
What could be more simpler you might ask?
A complete solar (Green) system.
Both are available thru me. E-mail for more information and prices...

2+stroke+ made it!(author)2009-04-10

you can place a large container under your down spout throw in another pump and time it to refill whenever you want mark a level on your main water reservoir and drill a hole and put a tube in your hole and run it outside

Grathio made it!(author)2009-04-14

I'm not sure I totally understand what you're saying. (Capital letters and punctuation would really help.) But it sounds like you're suggesting to fill the main reservoir from rainwater, which I think is a great idea! This setup isn't really made for outdoor use, it's intended for indoor plants, but with some filters and some weatherproofing it could work. An excellent addition!

Callum+Snowden made it!(author)2009-07-22

You could keep the main tank indoors and cut the bottom, off, say a pop bottle and cut a hole for a pipe to fill your main tank up. Then only the rainwater collector/funnel jig has to be outside.

2+stroke+ made it!(author)2009-04-14

I am sorry for my punctuation errors. I meant to put a bucket under your downspout put in a pump and run it off a timer time the timer when you want to fill the main water bucket , run tube into your house from outside and put it in your main water bucket .Extra water will have to overflow so drill a hole in your main water bucket and put tube to the outside of the house.

Grathio made it!(author)2009-04-15

Ah, I understand. Yup, that would definitely be possible and a great way to cut down on water use!

There's another great Instructable that uses water condensed from an air conditioner to water his outdoor plants. You could use a similar system as they use to collect this otherwise wasted water.

If you run a dehumidifier you could also use that to provide recycled water for the plants.

2+stroke+ made it!(author)2009-04-12

plz reply if it is a good idea

lucas.s.fragoso made it!(author)2009-05-25

Why not use only one bucket and one pump? You can measure the amount of water by setting the interval the pump will work lower or higher. If you want a bunch of water set it for 5 minutes, if you want just some drops set it for some seconds. Wouldn't this work properly?

Grathio made it!(author)2009-05-25

The double system is because cheap fountain pumps and $10 vacation timers don't provide very reliable control at all. I've never found a vacation timer that works on second increments, it's hard enough to find one that has minute resolution, most are 15 minutes to an hour.

Also these cheap pumps can't be relied on to deliver the same amount of water over a given time. I tested them pretty thoroughly and running them for 10 seconds one time would deliver several cups of water one time, and no water at all another.

As I said in my intro one of the features of this design is to make it reliable. Both to keep my plants alive and not pumping gallons of water all over my floor. Having the extra pump and timer makes it much more reliable.

However if you have a reliable pump and a programmable timer then one water supply and one pump is the way to go and you don't really need an Instructable to set that up. But in my research these things easily double the cost of the project. If you're interested in a more ambitious project, I suggest the Garduino Instructable which uses moisture sensors and a microcontroller to control the pump. It's a very cool project.

lucas.s.fragoso made it!(author)2009-05-26

I see... I do have a timer which is very precise, i can program it for 1 sec and it will work. But his pump problem would be an issue. I never used one of those, but I do believe they are not much reliable. Good thinking btw, you got a good solution with cheap stuff.... Great Instructable!

AndyGadget made it!(author)2009-03-26

Nice idea, but it got me thinking. I tried to think of a way of using only one pump/timer and came up with this. It's not quite as accurate but it would probably be good enough. The timer runs once per day and empties the underwater container (the tube to the surface is to equalise the pressure). The container then fills slowly over the next few hours through a very small hole (shown in the LHS of the underwater container).

Grathio made it!(author)2009-03-27

I think that's a great idea! I had thought of a similar version with only one timer (since the timers are more expensive than the pumps) that fed another container on a slow drip, but your idea is even more elegant. As you mention below you'd need to put the pump inside the sunken container with the slow leak, and vent it with a tube to the top. The accuracy would be +/- how much leaked in during the pump, plus the water that would fill the vent tube, but I wouldn't think it would be more than a tablespoon or more. Anyone else want to give this a try?

AndyGadget made it!(author)2009-03-26

Problem . . . My pump would have to be a self-priming type otherwise it wouldn't get started. Or a better solution would be to put it in the underwater container. It would then be ready-primed when the power came on.

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Bio: Creative swashbuckler. Writer for MAKE Magazine, presenter of inventions on TV, radio, magazines and newspapers. Professional problem solver. Annoyingly curious. Hacker of all things from ... More »
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