Rain Barrel Irrigation System Keeps Your Plants Fed When You’re Too Busy


[Kyle Gabriel] moved into a house with a nice tract of land behind it, but due to his busy schedule he had yet to plant the garden he so desperately wanted. He worried that his hectic life and busy hours would lead to accidentally neglecting his garden, so he built a water collection and automated irrigation system to ensure that his plants never went without fresh water.

The system is fed by two large 55 gallon barrels that collect rain from his gutters. A 1/2 HP well pump is used to pressurize the collected water, which is then dispensed throughout his garden by a sprinkler. [Kyle’s] system is run from a small control box where an Arduino is used to control the pump’s schedule. At a predefined time, the Arduino turns the pump on, while monitoring the system for potential problems.

If the system starts running low on water, the Arduino triggers the valve on his spigot to open, keeping the water level above the pump inlet pipe. He also keeps an eye on pump’s outlet pressure, indefinitely disabling it before a blockage causes the pump to cycle repeatedly.

He says that the sprinkler system works quite well, and with his modular design, he can add all sorts of additional functionality in the future.

53 thoughts on “Rain Barrel Irrigation System Keeps Your Plants Fed When You’re Too Busy

  1. Pretty cool, I have always wanted a smaller scale version of one of these, just for a couple of planter boxes and my bonsais, possibly with either drip spouts or the hoses that “bleed” water.

    Remember if you water late at night (2-3am) the plants get the most out of the water, as the sun won’t evaporate it before the plants have time to take it all in.

    One question though, is your enclosure a waterproof circuit breaker box? It makes a nice case either way!

  2. I really don’t like the exposed power prongs on the brick powering the arduino. soldering to the internal board or covering with heat shrink would really improve safety. 120vac is NOT friendly.

    1. i was thinking the same thing. Heat shrink over the exposed prongs and some plastic covers over the exposed 120 prongs of the SSR, even just a sheet of
      acrylic over them makes things much safer.

      1. Here are the two I am using. They’re a little more expensive than I quoted, but keep an eye out on ebay and they will pop up cheaper.

        Crydom D1225 Input: 3-32VDC, Output 120VAC 25amp

        Crydom D1210 Input 3-32VDC, Output: 120VAC 10amp

      2. My posts with links don’t show up, but if you do a search for “Drydom D1225” and “Crydom D1210” and sort by price you’ll find them. Keep an eye out and you should see even cheaper ones pop up. I had my phone notify me when a cheap buy-it-now auction was listed and I also followed classic-style auctions to get mine at the price above.

      3. Crydom, that is, but searching for misspelled auctions is actually another great way to find items that don’t get the publicity they otherwise would, and consequently sell for less.

  3. Good idea. Here in Colorado, USA, collecting rain water requires special permits. Please check local laws before dong this (neighbor was fined $2,000 a month for having a rain barrel under his gutter).

    1. Oops! I did not mean to report that comment! (Can we put a confirmation box on that or something?)

      I actually came here to compliment the idea of saving rain water for this purpose, why would someone be fined $2K for one barrel? I can see maybe a problem with large scale in certain areas, but not some small-scale hobbyist in his backyard.

    1. While the regulations are long over due to be updated understanding history goes a long way to understand whey they exist in the first place. In the “land of the free” persons where free to modify natural stream flow hoarding all the rain for themselves depriving those downstream what nature provided for who knows for how long. KS periodically take CO or NE to court to enforce water rights agreements. Either court proceedings or send the KS air National Guard to take out dams ;)

  4. Sorry, comment system defaults to a response for some reason.

    I meant to ask this as a new thread:

    Do those SSRs have enough cooling? I don’t see a heatsink. Is leakage current a problem with them at all?

  5. I also don’t like how he attached the incoming 120V into the arduino power supply. At least solder the joints rather than stick wires through the plug holes and bend them over as it appears to have been done here.

    1. They are soldered. although I have considered heat-shrinking the solder joints, this box wouldn’t be opened by anyone but myself, so there’s little risk if care is taken within the box.

  6. Nice project, but if any electrician sees that box he’ll be legally required to punch you in the eyeballs.

    Seriously – 120V bent around a wallwart plug and exposed connections on the high-voltage side of the relays?

    Have some pride, man!

      1. I’m pretty sure the alternatives are glaringly obvious to every single person who can see the picture at the top of the article.

        I can understand the loose standards for a prototype, but this is too exposed for me for a final design. I’m typically one of the readers who thinks the safety comments are unwelcome, and if you have an issue you’re just a wussy. Despite this, he needs to spend 15 minutes with some heat shrink and RTV to ensure he won’t have a problem down the road.

    1. Then the fight would be on ;) with an ignorant self-righteous electrician. A reasonable assumption is like an electrical service panel would be that only a qualified builder/installer, or service tech will be inside the enclosure. Clearly the wires are soldered, and this method is not any different than connect wires to a tube socket or terminal strip. They aren’t any more exposed than terminals on the receptacle and relays. Not to mention the underside the chassis of vacuum tube equipment, where voltage levels are often much higher.

    2. @kyle

      You have a valid point regarding the connection points on the SCRs. Ideally the box would be separated into separate regions with proper separation. In this case there can be a cover over all HV circuitry that has to be removed in order to access it. This would negate the requirement of covering exposed HV points, at least as far as I’m concerned.

      If I were to have designed this in exactly this manner, I would have heat shrinked the terminals on the wall wart, and simply put a bit of RTV over the terminals on the SCRs. RTV is easy enough to remove if you need to access the screws below it, and incredibly robust.

      Also, I sure am glad that when you enter an invalid email and hit submit it doesn’t make you retype your entire comment haha…

      1. One part RTV can be quite bad for electronics. the vinegar smell is acetic acid, same stuff that gives vinegar its smell and sharp taste.

        The acid part is what’s bad. It can cause corrosion, especially when the RTV is applied thickly or a sealed box is closed up before all the acetic acid evaporates, which is what cures the silicone.

  7. oh, didn’t see the PS wiring.

    I’ve done female disconnects for 14-16 ga wiring, slid them on the PS blades and shrunk tubing around them for using an off the shelf supply.
    Got those in a couple of work projects. Makes for quick replacement when problems arise.

  8. If there are any electricians or similarly skilled individuals reading, with knowledge of regulations, fire code, etc., I would gladly listen to any suggestions for improving the design for safety.

  9. the line providing city water shouldn’t enter the rain barrel but end one inch or more above the barrel. that air gap will prevent siphoning or “backflow” (washing machines have that setup).
    you could also get a “vacuum breaker” for the garden hose for around $3. most cities have that as an ordinance.

    1. I should have put photos of the valve setup, but it works in the way you describe.
      It does go into the barrel, but it is a hole that is bored at the highest point of the barrel, above the highest potential water line.
      There is a drainage hole on the other barrel that will allow excess water to leave the barrel rather than overflow from the gutter feed line over the top of the barrel and onto the pump. This is what keeps the water level below the hose from the spigot.

  10. FWIW, if you want an easy, natural way to help your plants deal with drought conditions, biochar can help:


    – Solely mechanical soil improvement
    – Functions like a coral reef for sheltering soil micro-organisms
    – Holds water and nutrients until plants remove them, keeping both from leeching further down into soil, and water from evaporating upwards.

  11. There are certainly many people who complain about the unprotected 120v areas, even if it’s inside a closed box.
    I can see that it will be best if I keep some of my designs away from the internet, since they are much more unprotectet than this one, and i live in a 230V country.

    PS: Really great looking photos on your webpage Kyle.

    1. Thanks.

      Yeah, it’s hard to argue with people that it is protected by the thick plastic cover encasing it. It should be unplugged when working near the HV anyway.

      A comment above was correct in stating only the installer, trained technician, etc. should be entering enclosures like this, and it is no different for this one. First, the box is incredibly difficult to open (without a lock), but this box also has a 4-digit combo lock securing it. Although, I expect someone to chime in with the fallibility of my lock, yada, yada.

  12. A few safety notes:

    1) That Crydom D1210 SSR is only rated at 10A, but it’s in a line whose upstream breaker will be rated at either 15A or 20A. If something goes wrong with the load after the SSR, you’ll exceed the rating of it before the breaker kicks on. Even if there’s no plan to run more than a 10A load on that circuit, remember that the breaker there is for the unplanned events.

    2) The wrong polarity is being switched on the AC line. The black wire (hot) should be switched, not the white (neutral), since doing it the other way around means the device on the other end is always energized but lacking a return path. It makes for the possibility of thinking a device is safely powered off, when in reality it has power but is just waiting for a path to ground; that path could be a person touching a component they thought wasn’t energized.

    3) The polarity of the outlet is wrong, which is especially bad considering issue #2. Now the load is not only energized at all times, but the wrong half is hot, which makes the risk of injuring someone who expected the component to be wired as per code that much more likely.

    4) As this is powering something outside of the house, there really should be a ground fault interrupt (GFCI) in there somewhere. The motor load might not be happy with a standard household GFCI, but as you’ve got water and outdoor exposure combined with electricity there should be one in there.

    5) Standard NM-B (aka Romex) cable was used to make an extension cord to wire the motor load, and outside of the house no less. That stuff does very poorly outside, and should be replaced with a properly rated cable.

    1. 1. The loads on the SSRs are only 40-60% (Norm-Max) of the max for the pump SSR and ~10% for the valve SSR, but valid concerns.

      2. The positive is being switched. Don’t let the color throw you off, it was a bad design by whoever made the extension cord I used. I was surprised, also.

      3. See #2.

      4. With it being said that this was partially constructed from components I already had, I would agree that a GFCI would be the next logical upgrade to drastically improve safety.

      1. There is no “positive” as you mention. The black wire is always “hot” and the white is always “neutral”. The hot will be 120VAC from both neutral and ground. There will also be 0VAC from ground to neutral. You have it miss-wired. Also, the smaller prong on the outlet is always hot and the larger is always neutral. You also have this miss-wired. This should be fixed, or as Bryan said, you are creating a dangerous situation. Also, you should not be using those green wire nuts on anything other than ground wires, but that’s a code compliance issue.

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