DIY Auto Watering System

If you think being around to water your plants might be a problem, then a DIY Auto Watering System might be what you need to solve it. With the correct setup, you can fill a reservoir with nutrients, and then be assured your cannabis plants will be watered automatically.

This can be great if you work away from home throughout the week. If you only come home from work on the weekends and want to grow weed, or maybe you have a holiday or vacation coming soon and you won’t be around to water your plants.

An auto watering system for your weed plants is easy to set up, cheap, and makes the whole process of feeding your cannabis plants a lot easier.

Buying an Auto Watering System for your Grow Room

This pic shows the Ebay Auto watering system

You can buy an auto watering system for your grow room from Ebay or Amazon for a decent price. However the problem is, sometimes these may not be adequate for your grow room.

For the best result and for a better price, you should build your own DIY Auto Watering System so it is more suitable to your grow room

I have used a set up bought from Ebay in the past. and I ended up needing to build my own Watering System as it wasn’t adequate enough for growing four weed plants.

I decided I needed to get a Watering System that was more capable.

This year as the season gets ready to start. I have decided it’s time to either build my own setup, or possibly lose my plants. So after a little trial and error, the resulting set up will pump 1.6l in 60 seconds per ring. For the most part this is the amount that I hand water, and therefore the plants should be much happier.

Controlling DIY Watering Systems

This pic shows the Digital timer used to control pump run intervals and days of operation for the DIY Auto Watering System

So for the build I decided to use a digital timer. This allows me the ability to program the system for 1 min intervals and also select the days of operation. .

Constructing the system drip rings

This pic is showing the assembled drip ring before adding holes.

The drip rings will be used to deliver water to the surface of the soil.

First I began by cutting off 4 lengths of tubing 24″ a piece, Then using 4 “T” fittings I constructed 4 Drip rings.

Next I drilled holes in the drip rings to deliver the water to the soil. To do this I decided on using a 5/64th drill bit. Then I decided to start with 2 holes in the ring and work up to more if necessary.

After testing they ended up with 3 holes.

Pumps For DIY Watering System

Pic of a Fountain pump being used to provide flow for the auto watering system.

I will be using a fountain pump to provide the needed flow of water to the drip rings.

The pump I have is capable of flowing 320 GPH, a much smaller pump would be better suited for this purpose.

Adjusting system flow

Pic of the fountain pump inlet showing the adjustable inlet used to help control the flow rate of the DIY Auto Watering System.

The pump I used has an adjustable inlet, which is useful for tuning the flow rate of the DIY Auto Watering System. Opening and closing the inlet allows for adjustment of the rate of flow, Thus allowing you to fine tune the auto watering system to meet your needs.

Final Assembly of the DIY Auto Watering System

Pic of the system set up ready to test

I started out by placing my buckets in position and then placing the pump in the reservoir.

next I cut several pieces of tubing to fit and connected all the drip rings to the pump.

Make sure all fittings are firmly attached, the last thing you want is water spraying all over place or possibly contacting electrical devices.

Now your DIY Auto Watering System is ready to test.

Time to test out the DIY Auto Watering System

Picture of a drip ring in action flowing water into bucket

Once I plugged the pump into my Digital timer and programmed it for 60 seconds, I was ready to test the flow rate of the DIY Auto Watering System.

Once the cycle was complete, I could now measure the amount of liquid. I ended up running the system 4 times to ensure accurate measurements.

Measuring the final system flow


To measure the flow rate I emptied the contents of a single bucket into a measuring cup.

I measured each bucket separately, In order to determine the individual flow rate.

The results were approximately 1.6l of water per drip ring.

Since this is close to the amount that I use for hand watering no further testing was required.

And my DIY Auto Watering System is ready for operation.

I hope this helps anyone in a similar watering situation

I now feel confidant that my plants will be properly watered while I am away working this season. And feel that it may also work good with my scrog, where it can be difficult to reach the plants in the back.

For more information on equipment for growing weed, check out the How to Grow Weed Sections

Now I need to find a bigger reservoir Happy Growing

Parts list

For using 1/2″ tubing

1/2″ pvc fittings

Water pump

Digital Timer

1/2 ” PVC tubing

If you have any questions or need any advice with setting up your own automated watering system for your plant, the you can find me in our cannabis growers forum. Sign up now, and start a new thread in the hydroponics section. There will be someone to help you straight away.

Thanks for reading Percy Growers.

18 thoughts on “DIY Auto Watering System”

  1. All I can do is tell you what I did and still do. My grow is coco with perlite using Advanced Nutrients Sensi Coco that uses the ph perfect tech so it balances and maintains ph for up to 7 days if mixed correctly. I’ve gone as long as ten days without problems. On 350ml mug grows I fertigate every 2 hours with lights on and every 4 hours lights off. It’s overkill for sure but like you said with coco you can get away with this but the top of the coco was algae covered by the end, no problem for the plants tho. On the 60ml grow it gets fed every hour because I can hardly get anything in the bottle. When growing in 3 gal pots I fertigate 3-4 times a day to increase growth and yield. I’ve not used amended coco so no clue there. To help prevent slime buildup I put air stones in the res on a timer set to run 15 minutes every hour. This was enough for me to prevent the solution from going bad. From earlier experience I knew that too much air bubble in the feed will cause fast ph drift. I always use either rainwater or RO water because it’s easier to stabilize the ph for me. Not sure if any of this helps but if you want any other info just ask brother. Your solo cup experiment looks to have some promise.

  2. @monkeydo @@twisted1 @templegrower I would like your advice and ANYONE ELSE that are familiar with these systems.  I just bought a “moistentland" 😂 great name lol

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     I have done a previous grow using a DIY fold and drain setup but recirculated and topped up for 3-7 days before a full water change and res wipe down.  Everything got dirty very quickly😅.  Within about 2-3 weeks their ways some discolouration on the tubes and salt stains on the res.  After 4 weeks ish there was the “slime" and solidified salts.  I didn’t add any H2O2 to the nutes but still don’t want this to happen again.
    I’m planning to use this unit for a micro grow probably using amended coco.  Figure if I can just run water through it I won’t need to clean it as often and if its coco over watering shouldn’t really be an issue.  Although solo cups could be an issue with the right mix that feeds long enough but doesn’t burn at the start.
    Was wondering what ya’ll recommend?
    Watering frequently/amount/schedule? Water source (tap water, treatment for tap water, ro, spring, distilled), if I add H2O2 will it kill the amendments?, Medium mix ratios? Ph? Maintenance? If this is a horrible idea?
    Thank you in advance, any advice would be much appreciated.  

  3. @twisted1I am going to take a video of my build and how I do what I do. here are some resources I use for building a grow. 
    –  This is great for building your own flood tables. I just use a window squeegee and build a half box minimal side size of 6 inches and let dry for cure period.  Works great!!
    And for most parts, I go to Amazon. 
    I may post my calculators for media, water needed Needed pump volume, etc.  If you guys/gals want to know let me know so I have a need to post it all!

  4. @twisted1 – Seeing how you did this is nice but noticing you are using buckets it seems it would be better for you to use a flood and drain style watering system to minimize algae on the surface of your medium. Any light contact with water produces problems. If you water ebb and flow but leave 2 inches of space from the top of the medium you limit algae growth and deliver oxygen to the roots more often. You can use soil but the flow of water would need to be really slow. I find hydroton mixed with coco chunks works best. Especially when you go auto syphon and plumb them together. (I’ll post an example as I am building one now for a grow.) I will most likely post a video link to the build to give more in-depth system assembly and auto syphon specs. I use the auto syphon to check ph, EC, and TDS, I just find it more simple and easy to use. 

  5. @monkeydo Nice thanks Monkey I was not looking forward to trying to fill and store a large barrel on the second floor of my house, Multiple smaller ones would definitely be easier to handle.  I have a lot of PVC pipe and fittings laying around.

  6. Here’s an easy and cheap way to scale the system to allow more time between refills. I made siphon links to link multiple buckets. They are simple U shapes out of half inch pvc scraps. The bottom should be cut as a slight angle to assist flow and you can link as many as you want. Just fill the links and insert them into the full buckets.

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     I’ve been away as long as 10 days auto watering without issues. 

  7. @monkeydo Thanks monkey I also have the black tubing that i can use for the other 2 rings. I just used what i had on hand at the moment. My idea is to place the res out side the tent and can also add to it so i can also water my second tent. I have the smaller system from ebay that i will use to pump nutes with on one day each week.

  8. Good job Twisted, these watering systems can really help reduce some labor in your grow. Been using a modified version of this for a while now and as long as it’s maintained properly it’s a real improvement in any grow space. I’ll share a couple of lessons I learned to maybe help someone else avoid my screw ups. Moving only water is different than moving nutrient rich water as algae and slime build faster in nutrient water. It’s good to have the system that can be disassembled and cleaned as needed during the grow. I ended up making my rings so they can be removed to be cleaned and also so I can remove plants to clean the tent if needed. The fertigation rings can clog with debris and slime if not serviced. The pump in a nutrient rich solution will also need cleaning periodically for the same reasons. I try to clean the system weekly and never longer than 2 weeks. My res is outside the tent so it stays out of the bright light and avoids algae growth better, dark color res with light blinking lids are recommended. Avoid using clear tubing, black is better to prevent slime and algae buildup and clogging. And lastly, auto watering is great but you will still need to hand water periodically to ensure even watering and help properly flush your medium.

  9. Excellent work twisted, thinking about setting one of these up myself man. Save me some time, and it’ll be nice to be able to mix feed when i have time to and not have to wait until lights on n shit. 

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