How to individually send water to each specific plant with only one pump

Hi,

Been reading through some great watering system / irrigation system tutorials online. Most of them send equal amount of water to all plants, or use a directional "gun" to squirt water at the relevant plant.

I've been trying to find other alternatives to ensure individual watering of each plant. I will need moisture sensor per plan, and an individual hose as well.

However what alternatives are there to control water to a specific hose? I found that there exists 4-way hose faucet but only manual ones. I guess I would need an electric one to control the flow of water.

First step is to find a solution that can water one plant at a time. Alternatively would be to find a solution that can send water to more than one plant at a time... I'm planning to create a small scale system to water my herbs on the balcony, so only need small tubes.

I plan to water up to 10-15 individual plants, all within 2-3 meters from the pump/arduino setup.

Hope for help and alternatives.

you have a lot of options.

most solenoids require high pressure to operate. that means if you are using your house water, you have enough pressure. if you are using a small pump, then you need to get solenoid valves that do not require pressure to work.

you can use a pump or valve, fill a large hanging bucket and that has lots of hoses at different depths. the ones near the top, only get a little water, the ones at the bottom get more.

you can put your plants on wire, then saturate them, let the excess drain away.

you can put in moisture sensors and then hoses, each hose to a solenoid, or each hose to a larger connection. use a couple of servos to position your water cannon to spray water into the ends of the pipes. you can time or each plant so you deliver how much water you want.

lots of options, depends on your space and what you have available.

I think there was a guy who made a large box seat, put the reservoir in that and all the pumps and such and ran tiny tubing to his plants.

Hi,

Haven't found an electronic version yet. If nothing exist, would it be possible to buy a manual tube/hose with a shut-off valve and connect a servo motor to control the valve?

Years ago we used a device in our wind tunnel models called a scanivalve that allowed you to select which tube you were connecting (sort of like the old stepper relays used in telephone systems). You may be able to find something along those lines (or search for rotary valve) that would allow you to select which tube you were feeding. The other option would be to experiment with the control valves for sprinkler systems, but I think they require a minimum pressure to operate correctly (they have a 24VAC solenoid to trigger them, but then use pressure in the line to actually move the valve if I remember correctly).

These are under 5.

http://www.banggood.com/Wholesale-Black-Windscreen-Windshield-Washer-Pump-for-2000-2007-Ford-Mondeo-MK3--p-60984.html?currency=GBP&createTmp=1&utm_source=google&utm_medium=shopping&utm_content=saul&utm_campaign=pengyuanlai-uk&gclid=CjwKEAiA9c-2BRC_vaaJ0Ybps30SJABlqxDezvxIPxoTLNnklEp0AedPnoYlG6fZR7H9BtSYnLW8URoCBFrw_wcB

A single solenoid could cost more.

Use one for each plant perhaps, with an ani syphon loop.

I have used these before. http://www.fimcomfg.com/products/hydro-indexing-valve/

Hi,

I found some cheap 1/2" ​Electric Solenoid Valves on eBay. It seemed like the best option given the price of the other suggestions.

I'm hoping that by starting the pump a few seconds before opening the respective Solenoid valve, it can build up the needed pressure in the hose to work. Unsure if the pressure is needed to open the valve, or to keep the valve open. The Electronic Solenoid valve that I bought is this one (link)

The datasheet state that is needs a pressure of 0.02- 0.8Mpa to function. Not sure how much this is and if this pump (link) can supply the needed pressure, but I hope so... I will create the watering system based on either 1/4" or 1/2" PVC hose.

I really like Boardburner2’s windshield washer pump idea, to bad banggood links never work.
But on ebay I found a us based source for $4.
ebay windshield washer pump

Hutkikz: to bad banggood links never work.

see that last 5 digit number ?

try that

"http://www.banggood.com/Wholesale-Black-Windscreen-Windshield-Washer-Pump-for-2000-2007-Ford-Mondeo-MK3--p-60984.html?"

i took off the quotes and final question mark and went to the link.

Boardburner2: These are under 5.

http://www.banggood.com/search/windshield-pump.html

A single solenoid could cost more.

Use one for each plant perhaps, with an ani syphon loop.

I think these are self priming ? connecting a few to some pipe would not be that hard and if you use a rubber type fuel line hose, you could take them off if they needed to be cleaned or replaced.

Christian_83: Hi,

The datasheet state that is needs a pressure of 0.02- 0.8Mpa to function.

It also says not suitable for gravity systems.

That probably means it will not work well with low pressure.

Hi,

Do you know if the Electric Solenoid Valve needs the pressure to open, or to stay open?

Do anyone know how one can calculate if the pump will be able to build up enough pressure in the PVC tube to meet the requirements of the Electronic Solenoid Valve.

Christian_83: Do you know if the Electric Solenoid Valve needs the pressure to open, or to stay open?

Yes.

Christian_83: Hi,

I found some cheap 1/2" Electric Solenoid Valves on eBay. It seemed like the best option given the price of the other suggestions.

I'm hoping that by starting the pump a few seconds before opening the respective Solenoid valve, it can build up the needed pressure in the hose to work. Unsure if the pressure is needed to open the valve, or to keep the valve open. The Electronic Solenoid valve that I bought is this one (link)

The datasheet state that is needs a pressure of 0.02- 0.8Mpa to function. Not sure how much this is and if this pump (link) can supply the needed pressure, but I hope so... I will create the watering system based on either 1/4" or 1/2" PVC hose.

put the number into google .02 mpa to psi google does the conversion 0.02mpa = 2.9 PSI or about 0.2 atmosphere figure about 10 feet of head on a pump, just to open the valve. not sure of the characteristic of the open valve and flow through it. field testing would be in order

all pumps are rated by head pressure. all pumps have a table that shows flow as a function of head pressure. few, if any e-bay offers have these data sheets and you may need to search for the model number and in the google search results, hit translate this page.

you are in uncharged territory of getting parts to work close to their operational thresholds. chances are the solenoid, mounted below the pump, will allow water to pass. how much is unknown. you can do field testing, or go with zero pressure valves. or a higher rated pump to get into reliable areas of operation. a hose with city water will deliver more water pressure and flow than you need. use that if possible.

a note about windshield washer motors, they are made for very short duty cycles, like running for 5 seconds out of every minute. for the price, get a spare. if any do fail, you might be able to make bushings from nylon to extend life to years.

Paul__B:

Do you know if the Electric Solenoid Valve needs the pressure to open, or to stay open?

Yes.

simple answers are often best in engineering.

I believe a solution with one pump per plant (pumping from a reservoir) is better.

These are 1.42€ if you take ten. DC 3-6V Micro Submersible Water Pump solar pump 120L/H fountain aquarium Free shipping

Here is a quick and dirty performance curve for the pump in reply 6. Flow rate is in mL/min and pressure is in inches of water. As I recall, the pump was supplied with 6 volts for this test.

(Flow, Pressure) 0, 36 200,25 300,20 400,13

Whandall: I believe a solution with one pump per plant (pumping from a reservoir) is better.

These are 1.42€ if you take ten. DC 3-6V Micro Submersible Water Pump solar pump 120L/H fountain aquarium Free shipping

Hi Whandall,

I did actually think about this solution. First I thought that the downside of this option is that you need one tube per plant from the reservior, while the other one can share the tube to a certain point. However that is only the case if you have the pump in the reservoir. If you have the pump close to the plant, where you would alternatively have the solenoid valve then you can also share the tubing...

So it might as you say be better to have one pump per plant. If I am going to have one moisture sensor per plant anyhow, I need to pull a cable to the plant anyhow.

I guess the pump will be equally strong at pulling water from the reservoir 2-3 meters away (up to 1.5 meters up) as it would be at pushing the water the same distance.

I have ordered ten of those cheap pumps and will try them. I could not find solenoid valves in that price category.

Whandall: I have ordered ten of those cheap pumps and will try them. I could not find solenoid valves in that price category.

They are not generally self priming and need to be mounted below the water level.

The outlet pipes should be above the water level to avoid syphoning.

Just like in a car.