Category Archives: Projects

Sonoff eWeLink New Lawn Irrigation Scene

Link to Irrigation Blog

My existing Sonoff watering control comprises of a Sonoff Basic to turn the irrigation pump ON/OFF and a Sonoff 4 Channel Pro which controls which set of lawn valves to Open/Close.

My existing setup had an automatic scene to water the lawn when the grass had established, however, I wanted a Scene to automatically run for a newly seeded lawn which just kept the seed moist by frequent watering, but short in duration so as not to wash the seed away.

My existing system has a Rain Sensor, so if it has already rained, the scene would still run, but the power supply to the irrigation pump is removed until the rains sensor is happy.

List of Requirements:

  • Water the lawn every 3 hours
  • Start watering at 06:00
  • Stop watering at 20:30
  • Sprinkler duration 5 minutes

How:

I had to use another Sonoff Basic as a Smart Device trigger to start the irrigation scene.

  1. Triggering Basic device setup to have ‘Inching’ enabled with a short duration ‘ON’ time
  2. Set up a schedule to turn the Basic on at the required times, (no OFF time is required as the Basic is in inching mode)
  3. Turn the Basic schedule ON and save
    1. Create a new Scene
    2. Set the IF action trigger to be the Smart Device Basic
    3. Set the THEN actions

    In my scene, the following happens:

    • Scene triggered by the Basic switching at the scheduled time
    • Then, irrigation pump turns on
    • And, the Irrigation Controller (4 channel Pro) switches power to Open sprinkler valves on two sections of my lawn
    • after a 5 minute delay the Irrigation Controller closes the two valves and opens another lawn areas valve
    • after a further 5 minute delay, the irrigation pump turns off
    • 5 seconds after the pump turns off, the irrigation controller closes all the valves (delayed to allow the water pressure to fall)

    I had help with this from the eWeLink & Sonoff User Group on Facebook and in particular Stipan Retkovac who has extensive knowledge in this area and to whom I particularly grateful.

    Lawn/Garden Irrigation Project

    Blog updated 6 October 2023

    UpdateLink to New Lawn automatic watering Scene

    Introduction

    In 2022 I decided to invest some time and effort in getting the lawn in shape after years of neglect, so I followed a number of lawncare YouTubers, and with their advice, the lawn has never looked better even in winter.

    11/12/22 -4.2c
    11/12/22 -4.2c

    Unfortunately July 2022 was the hottest (currently) temperature ever recorded in the UK, and lawn watering was needed to keep the lawns (total area 117m2) in good shape, this took ages to do as my mains water pressure is poor and I have three separate sections of lawn, so the idea of an irrigation system tailored to my lawn layout was formed, I did have some experience, as I installed a simple Gardina pop-up sprinkler system at my last house in 1997, the difference being that the pipes were laid before the topsoil for the lawn.

    I jumped back onto YouTube to start learning about irrigation system technicalities, and this blog is about how I installed my system.

    Safety before you dig

    As the irrigation pipes in my system needed to be buried rather than an above ground system and I’m digging near the pavement , I checked with Line Search before starting any works. This is a free online service, using this portal enables multiple interested parties to let you know if they have a pipe or cable near where you are working.

    Not all companies are signed up to Line Search and during my hand digging I did exposed an Openreach telephone duct just inside my boundary which I did not expect!

    Line Search did identify close proximity to Gas and Electricity services:

    Anglian Water and Virgin Media services are also on my property but not identified by Line Search, I did make sure I knew the path these took before digging.

    Irrigation Design

    Fortunately a lot of information is readily available on the internet from manufactures, the two key players seem to be RainBird and Hunter, I downloaded the Hunter guide, so it made sense for me to deign around the guide and use their products.

    Following the guide, I needed to find out was the static water pressure and water flow rate available to me, using a Toolstation pressure gauge connected to the outside tap which is fed directly of the incoming rising water main, here I recorded a spot reading of 2.7bar (40psi).

    Chatteris is at the end of the water supply pipeline and the pressure can get quite low at times depending on upstream demand.

    Flow rate was also measured at the outside tap, the flow rate was calculated at approximately 35 litres per minute, (timed bucket method, (I did confirm this later using a weir cup).

    A quick glance at the Hunter products indicate that the optimal water pressure is 2.8 bar at the sprinkler head, therefore, I knew I would have to use a break-tank and pump to give me assured operation without dependency on the incoming water pressure.

    Using Visio, I drew out a scaled drawing of the house and garden in order to work out the spray head coverage, pipe runs including pipe lengths and types of fittings needed.

    It is important to work out pipe friction losses so that the pipes used are not undersized which would give an unacceptable pressure drop at the furthest sprinkler head.


    Digging Plan showing pipe routes, head placement and predicted water consumption, a full parts list can be extracted from this.
    Drawing showing scaled spray coverage pattern confirming head types.
    Drive dig underway, to Zone 3, the 20mm water pipe will be inside a 32mm duct (waste piping).

    Additional Hunter Design Information:

    Digging Method: I first marked the sprinkler head locations on the lawn with a blue spray in positions from the dimensioned drawing, using string as a straight line to follow, the Lawn Edging Knife was used to cut a section of lawn approximately 12cm wide by 14cm long (4.3/4″x 14″), using the trenching shovel to get under the cut grass and levering it out for replacement later.

    The width of the trenching shovel is 10cm (4″) about the same as the width of my boot which is handy for compacting the sand and soil later.

    The depth of the trenching shovel is 20cm (8″) which in my case is adequate as water will be removed from the pipework over winter and also my aerators hollow tines are 12.5cm (5″) in length so I should avoid damaging the pipes when I aerate.

    The builder left all sorts of bricks and debris everywhere before they put a layer of soil on top for the lawn, this made digging very difficult in places and the crowbar was superb in making a hard job easier.

    Once the trench was cleared of stones and the trench bed flat, a layer of sharp sand was added to bed the pipe on, the pipe, even thought it was only 20mm needed pining down with stakes to keep it straight, a second layer of sharp sand was put on top of the pipe, then a marker warning tape followed by a bit more sharp sand, all compressed at each stage by a size 9 boot.

    I used Levingtons essential top soil to fill the remaining trench, the first layer is compressed well down, the second and final layer is loosely laid so that when I place the cut turf back and ‘persuaded’ it down with the back of my shovel, the soil has somewhere to go.

    When the turf was re-laid a sprinkling of top soil was added to fill the joins and brushed in, then liberally watered.

    The tools used to dig were :

    Silverline lawn edging knife
    Roughneck trenching shovel 48″ from Toolstation – code 57538
    Bulldog chisel and point crowbar, model 60-BCB60CP from Travis Perkins.

    Above images are after a month of the sprinkler feed pipes being buried, showing just how resilient grass is.

    Break-Tank & Pump

    I bought a used Wydale Plastics 500 litre upright water tank from Facebook Marketplace for £40 , this is perfect as my break-tank.

    The term break-tank means their is no direct connection to the incoming water supply, the water filling float valve is positioned to maintain an air gap to eliminate any cross-contamination risks with the incoming drinking water supply.

    On my system, the break-tank can be filled in two ways, the primary method is via a 22mm feed from the incoming rising main to the float valve on the break-tank, this feed has a full bore isolating valve, double check valve and drain valve in-line for maintenance.

    Valve 15 is the 22mm feed to the break-tank.

    The second means of filling is from a submersible pump connection in my vehicle inspection pit, in normal use, the 15mm line from the break-tank to the pit will act as a break-tank overflow line.

    Break-tank overflow into pit, the pit holds 4,476 litres (1,183gallons), so very useful storage for pumping back to the break-tank, the grey pipe is from my gutters so I can harvest rain water.

    If the pit requires pumping out or if the tank needs filling without using tap water, the submersible pump will be connected to the 15mm overflow line, and this will be used in reverse to fill the break- tank, to catch any debris, a ‘Y’ strainer is fitted inline at the tank connection.

    The inspection pit holds approximately 4476 litres or 1183 gallons.

    Break-tank in position before the pump and valve box are installed.

    At the base of the break-tank is a 3/4″ full bore lever valve feeding a small 22mm manifold off which the sight glass is fed, actually is clear plastic pipe, but sight glass sounds better 🙂

    The manifold also connects to the Clarke SPE1200SS pump suction via a ‘Y’ strainer, the pumps delivery feeds the valve-box manifold assembly via a 80 mesh inline filter at 4bar pressure (58psi).

    The thread pitch’s are quite course so a good sealant is required, I used a combination of PTFE tape and pipe thread seal (Screwfix 4373J).

    Pump positioned inside an Argos Toomax 90L Patio and Balcony Chest 265/4351 to keep it out of the elements, ventilation grills were added as I found the pump runs warm. An 80 mesh inline filter is used to try and protect the sprinkler heads from blockages and the automatic Air Vent keeps the system primed.

    Finished pump and valve assembly, pump enclosure has had a side vent fitted, a sight glass tank level gauge installed and the water supply to the break-tank is now metered so I can check on how much the system costs to run .
    4 Oct 22 – 0 -6 Bar pressure gauge added to pump delivery to monitor the system performance.

    The last stage was to eliminate sunlight getting to the break-tank in order to stop water borne algae growth which will eventually block the water filters, I decided at this point to insulate the break-tank even though it will be empty over winter.

    I used 25mm polystyrene sheets to insulate the break-tank and to weatherproof this, I used black opaque floor protective sheets from Wickes which was perfect all held together with Lidl black duct tape:

    Revised Tank Piping

    I’ve made a few changes and additions to the break-tank pipework:

    • Added 22mm drain valve to lowest part of tank feed pipe
    • Added 15mm valve above overflow line isolation to enable me to place the tank on circulation
    • Added 15mm and 22mm flexible hoses to enable pipe movement without damage

    Sprinklers & Water Usage

    The sprinkler assembly comprises of the spray body, sprinkler head and a water inlet, I opted for the Hunter PRS40 body with an assortment of MP Spray Rotator heads to suit my application.

    The benefit of using PRS40 body is that it has an inbuilt pressure reducing valve giving me flexibility on the pump pressure, the body limits internally the water pressure to the sprinkler head to 2.75 bar (40psi) which correlates to the sprinkler head data for spray patterns and water usage, this means that as long as the water pressure is greater than 2.75bar to the body along the pipe run and at the furthest point, everything should work as designed.

    The spray bodies water inlet is a female 1/2″ BSP, in order to connect to the irrigation main line, I used a Sprial Barb fitting – 1/2″ male elbow (Stock Code SF-SBE-050), two are needed, one on the spray body, the other for the 20mm pipe fitting.

    A semi-flexible pipe links the spray body and main feed pipe, this pipe is called Swing or Funny Pipe (no idea why!), the code for this is SP30. Part codes used are from Sprinkler Irrigation.

    My system uses 15 sprinklers with MP rotators:

    • 1 x MPSS530 – Side Strip pattern
    • 1 x MP2000 – 900 – 2100 pattern
    • 1 x MP1000 – 2100 – 2700 pattern
    • 12 x MP1000 – 900 – 2100 pattern

    Water consumption per sprinkler head is dependent on the adjusted coverage pattern, the rotator data sheet enabled me to work out the expected water volume, data also exists on the Growinsane website regarding emitters l/m, again this is dependent on adjusted flow at the specific emitter.

    • Total front lawn – design usage 19.2 l/m, measured usage 21 l/m
    • Rear planters and pots – measured @ 16.6 l/m

    The Hunter MP Rotator data I used can be found HERE, however, a revised Metric version is HERE.

    The rear garden has a number of the following emitters, the l/m value is for each emitter:

    • Emitter – Shrubbler 3600 – 4mm barb @ 0.55 l/m
    • Emitter – Potstream adjustable – 4mm barb @ 0.36 l/m
    • Emitter – Shubbler 1800 – 4mm barb @ 0.28 l/m
    • Emitter Spike – Spectrum 3600 – 4mm barb & adapter @ 1.06 l/m

    Watering

    I ‘tweak’ and constantly review the ‘run times’ now I understand how effective the sprinkler head patterns are at delivering the required volume of water to the lawn and plants

    Water gauge from AliExpress – £6.73 for 10.

    The volume of water filling the gauge drives the watering run time as I’m looking for an average total of 25mm per week on the lawn, (this is a cumulative total and will include rainfall).

    The MP Rotator heads deliver a soft watering pattern to avoid runoff and enable the water to soak in, using water gauges placed at random places across the lawns, the average water collected over a 10 minute cycle was approximately 4mm.

    This means that just over an hour of irrigation will give me the weekly total of 25mm, however, I spread the watering periods over early mornings each day as a minimum, if the lawn shows signs of distress, I increase the watering frequency as the whole topic is a ‘black art’ and along as my moisture meter is happy, so am I.

    2023 Lawn Watering Cost – Budget for it!!

    I started a watering schedule in April, this schedule, (duration and frequency), varied based on when I over-seeded and if we have had rain, another consideration was the lack of rain coupled with high temperatures, lots of variables all contributing to evapotranspiration!

    The actual cost for running my 15 sprinkler heads for a 117m2 lawn for 10 minutes costs £0.65p per day, this cost is made up of water charges and sewage/foul costs.

    To water my lawn for 7 days to give me >25mm costs £4.55 per week.

    Where it started to expensive was when it didn’t rain, obvious really :-), Example – June 2023 was a dry, warm month, with only 5mm of rain measured, so with a bit of over-seeding and to keep the rest of the lawn growing, I used 26.8m3 of irrigation water from the 4th June to the 22nd costing £4.54 per day.

    The costs used are based on Anglian Water, June 2023 charges, 1m3 (1000 litres) costs £1.68p, add to this the sewage/foul costs which are based on 90% the water used and cost £1.71 per m3.

    I’m estimating the irrigation system will incur additional water charges of £220 per season, (April to October), I will revise this once the figures are in, so please check back.

    Update – 27 June 2023

    I have taken advantage of the water authorities ‘New Lawn’ allowance before but I didn’t know until a chance conversation that you can request a ‘Sewage Abatement‘ for that does not use the drains, e.g. Irrigation & swimming pools. So instead of a 90% levy, this drops to 10% per 1m3.

    I spoke to Anglian Water and they simply record the fact you have called and at the end of the season you let them know how much water you have used on the lawn, I have a sub-meter for my irrigation system, but I double check this against my main meter, once the readings are given to them, they will calculate the rebate.

    I don’t know if I will have a problem at the end of the watering season with the Sewage Abetment process, as its all verbal, rather than formally documented, watch this space!

    Pipe Sizing

    This is probably the most critical element, if any of the pipes are undersized, then the pressure drop at the furthest point may make the system unusable at worst or poor forming at best.

    The information I had was, as a rule of thumb, that a 20mm pipe will pass 1000 litres/minute (l/m) and a 25mm pipe will pass 2000 l/m, as I had independent zone control, with the highest water demand zone taking less than 9 l/m, I went with 20mm MDPE pipe as the flow rate, pressure and pipe length all worked out fine for my lawn.

    It turns out that the sprinkler head water volume is when the head is at its full design pattern, a number of the heads in my system have had the coverage tailored to my lawn, therefore the water consumption is lower, allowing me to have Zones 1 & 2 on at the same time with no adverse effect on water pattern coverage as the pump pressure is healthy.

    Pump delivery pressure profile based on which Zone/s are in use.

    As stated earlier, the Hunter PRS40 bodies have an integral pressure reducing valve so they operate at their optimal water pressure which is 2.75bar (40psi), it is important therefore, that the pressure reaching the spray body is => than 2.75bar.

    Readings were taken from the pump delivery, the static pressure (no load), was noted 4.6bar and with Zone 1 only ON, the dynamic pressure (under load), from the pump drops to 3.8bar with Zone 1 and 2 ON which is fine.

    Initially I had the system setup so that Zones 1, 2 and 3 came on together, this did not appear to have an adverse effect visually on the rotator head pattern, but with a dynamic pump pressure of 2.6bar, which is below the optimal minimum sprinkler pressure of 2.75bar and it will be lower at the point of utilization due to pipe pressure losses.

    Armed with this information, I have reconfigured the Sonoff scene so that Zone 1 & 2 are ON together, and after a pre-set watering time, both of these valves close and Zone 3 opens for its watering duration.

    In order to be thorough, I ordered through a friend in the US, a MPADAPTER which allowed me to measure the dynamic pressure reaching the furthest sprinkler heads on each zone, determining if => 2.75bar pressure is being achieved, which it was :-).

    The majority of pipe fittings were from waterirrigation, MDPE pipe 20mm compression fittings require pipe liners (inserts), to stop any deformation of the pipe in the fitting, I was told it was ok to omit this, but as the liner are cheap, I didn’t think it was worth the risk of a leaking joint at some point in time.

    Getting a clean, square cut on MDPE pipe is important as it gives a good face for the liners lip to sit against and also it makes insertion past the fittings ‘O’ ring easier with a reduced chance of seal damage, to get a clean cut I used pipe shears from Lidl for £9.99.

    Jump Link to parts used.

    Zoning

    For the greatest flexibility and water consumption distribution, I decided on 4 zones, (from left to right in the valve box):

    • Zone 1 – Left Lawn Upper (4.82 l/m)
    • Zone 2 – Left Lawn Lower (8.76 l/m)
    • Zone 3 – Right & Centre Lawns (5.65 l/m)
    • Zone 4 – Line/Drip Irrigation (1.75bar pressure reducer fitted)
    1. The valve box roughly laid out to ensure ease of working on and that it left room for the pump enclosure.
    2. Irrigation lines roughed in and trimmed, also the correct depth dug to accommodate the valve box ensuring that the lid would be at the correct height above the ground.
    3. I used a wooden baton with pipe clips spaced at the valve outlet centres to keep the irrigation lines in the correct position without causing any strain on the valves.
    4. After the pipe were connected to the valves and the valves to the manifold, the valve box body was notched to accept the pipes and then placed over the completed assembly, rather than work with the box in place.
    5. Valve box all levelled and backfilled with pea gravel, decorative white stone is inside the box as I think it looks good, a 25mm conduit was ran from the controller to the valve, through this passes a 5 core 1.0mm2 cable, one core for each valve solenoid and a common return. All connections were made in an Wiska-Combi 308 IP66 rated enclosure.
    6. All tested and ready for closing up.

    Control

    Water to each irrigation zone is via Hunter PGV solenoid operated valves, these need 24vAC to operate, applying 24v will open the valve, with no voltage present, the valve will be in the closed state.

    1″ valve, Male threads, part number – HPGV1FCM
    ELECTRICAL SPECIFICATIONS 606800
        •    Minimum opening/operating voltage: 19 VAC
        •    Maximum recommended voltage: 28 VAC
        •    Current at 24 VAC:
       •    370 mA inrush, 210 mA holding, 50 Hz
        •    Maximum operating pressure: 15.17 bar; 1517 kPa
        •    Wire leads: 45 cm of 0.8 mm2 UL-approved wire

    Hunter do make controllers for their range of valves but I decide to make my own using a 4 channel Sonoff Pro2 as the valve controller and a Sonoff Basic as the pump control configured as a ‘scene’.

    Version 1

    The Sonoff devices are paired to home WiFi and operated through the eWeLink App or dashboard, these are extremely flexible devices and ‘scenes’ can be setup, so that the actions of one device can effect the operation of another.

    The channels of the 4 channel Sonoff controls the solenoid of that valve, initially I had the Sonoff set to ‘interlock’ mode, meaning that only one of the 4 channel relays can ever be ON, but once I was able to test the pumps pressure and monitor the sprinklers performance, I decided to remove the interlock enabling greater flexibility of operation.

    Sonoff Scene

    As this is a new system, I’m working through the best watering times, the ‘scene’ I have currently set, (a ‘scene’ is a pre configured set of events that automatically run when triggered), at 04:00 on Monday, Wednesday and Friday , valves 1 and 2 open for 40 minutes, then valves 1 and 2 close, then valve 3 opens for a further 40 minutes, valve 3 closes and valve 4 opens for a further 5 minutes.

    At the end of the 5 minutes, valve 4 closes and the pump turns off.

    Before going live with a scene configuration, I use a test rig to confirm operation of a scene before making it live.

    The scene below is to manually operate the watering schedule and can be easily ‘tweaked’ using the eWeLink dashboard:

    The scene breakdown is as follows –

    • The irrigation sequence is triggered by manually operating the app
    • 1st action is for the Sonoff Basic Smart Device to turn ON and supply power to the pump via a contactor
    • 2nd action is to enable a short delay of 3 seconds before the opening of the control valves , this allows the pump to prime
    • 3rd action is for the Sonoff 4Ch Pro relays 1 & 2 to turn ON, this in turn supplies 24vAC to the control valve solenoids allowing water to flow
    • 4th action is the Delay of 40 minutes, this is the period of time to elapse before the next action i.e. the valves are ON until the next action
    • 5th action, at the end of the 40 minute delay time, Sonoff 4Ch Pro relays 1 & 2 turn OFF and relay 3 turns ON
    • 6th action is the 40 minute duration that water will pass through valve 3
    • 7th action is that after the 40 minute delay time above, relay 3 turns OFF and relay 4 turns ON
    • 8th action is a 5 minute delay time before the Smart Device Sonoff Basic – Irrigation Pump turns OFF
    • 9th and final action is for relay 4 to turn OFF.

    I found quite early on that it was important to set up a ‘scene’ to turn OFF the Irrigation Controller relays and Pump as, in my case, access to physically operate Sonoff devices is not possible as they are within an enclosure.

    The Sonoff Basic has an internal relay switching 230v, this is used to operate a 20A contactor, which in turn is connected to a 230vAC 1700w water pump.

    The reason for the contactor switching the pumps load is to remove this burden from the Sonoff.

    A 230v/24v – (3.75A Max Output) Toroidal transformer is used to supply the operating voltage to the Hunter valves via the 4 channel Sonoff.

    Version 1

    Reverse side of controllers lid with information label.

    Version 1

    Front panel label, LED lights are from AliExpress, the ‘Pump Running’ LED is switched via a AC current sensing relay with the light only being illuminated when a pre-configured load is being drawn. This gives confidence that the pump is actually running, rather than simply powered up.

    Modified Irrigation Control V2 – Jan 23

    The original control version worked fine but it could benefit from two major improvements, these being:

    • Detection of water tank low level
    • Detection of rain

    The above is the amended version of the irrigation controller front panel, I use Visio to make the image to scale and print to A4 80gm paper, this is then covered in a self-adhesive transparent book covering affixed to the enclosure with double sided tape.

    The front panel has the addition of two override button and two red leds. each led corresponds to either the rain or tank level sensor, pressing the appropriate override button will illuminate the button and disable the input from stopping the irrigation pump from running.

    The drawing for the sensor circuit is below:

    The step down converter and relay module are contained within an IP rated Wiska box:

    The relay module has two inputs, one from each sensor (rain and tank level), when the sensor activates, the associated relay activates and provides the controller with volt free closed circuit.

    Version 2

    The additional parts in the revised controller version are 2 x 24vAC slimline relays and a Sonoff Mini2, the operation is the same as version 1 with the addition of a pump interlock if the tank water level is low, or/and the rain sensor has been triggered.

    Planter/Pot Irrigation

    This was the most difficult part of the whole project as I did not have an understanding of the parts, only an idea of what I wanted, fortunately the cost of parts is quite inexpensive, so if I bought the wrong thing it wasn’t so much of a big deal.

    The rear garden system starts at the water control valve, the pump pressure of 4 bar is too high and must be reduced, I used a Hydrosure 1.75 bar pressure regulator connected to the 1″ control valve outlet with a 1″ BSP female to 3/4″ BSP female reducing socket, the pressure reducer has a throughput of between 0.4 – 30 lpm.

    The reduced pressure irrigation water was fed to the garden via 20mm MDPE pipe, with branches made using Hydrosure compression Tee fittings with 1/2″ female offtakes.

    Into the 1/2″ female offtake a Hydrosure Director 13mm x 1/2″ BSP male is screwed in, and from this 13mm LDPE pipe is connected, this is the line into which the micro irrigation parts are pushed into.

    At each planter or main branch I fitted inline isolation valves, sprinkler emitters and shubblers simply push into the thin walled brown LDPE pipe, the use a key punch to make the holes is recommended.

    To the left of the picture you can see one of 20 Potstream emitters connected to the main line with 6mm OD x 4mm ID micro PVC pipe.

    Pipes can be buried and spray heads are very discrete.

    Picture shows a Shubbler 180 emitter connected directly into the LDPE pipe, unfortunately the clematis is struggling as the dog thinks its a lamppost.

    The micro irrigation emitters do not come with water usage data, I estimate that my system uses 27 litres per minute (lpm), this is just below the pressure regulators maximum throughput of 30 lpm.

    Winterisation

    The system will be drained during the winter months to avoid any issues with freezing, hence I was happy with the pipes buried depth and also the lack of below ground lagging.

    I have adjusted the original installation to include a fence mounted bib tap so I can benefit from the pumps pressure when watering the lawn, plus the water is separately metered, so I can claim back the sewage abetment payment, the byproduct of this is a connection point to blow all the water lines out.

    Although the break-tank will be empty over winter, I decided to insulate the tank when I was boxing the tank in.

    I already had a compressor (15CFM), so the parts needed to blow the system out were fairly inexpensive, these being a pressure regulator and adapter for the outside tap where the compressed air will connect to.

    The regulator was £9.95 from eBay, the tap and adapter parts are listed below (Screwfix):

    • Bib Cock outside tap -590FA
    • 3/4″ Female Socket – 52588
    • 3/4″ to 1/2″ Bush – 98427
    • 1/2″ to 1/4″ Bush – 79207
    • 1/4″ Male Adapter Airline – 2015H

    With the above, I connect the regulator, set to 2 Bar (30 psi) to the compressor with the regulated output , via an airline to the tap adapter on the outside tap, this worked really well for me.

    Instructions on my process are in the files below.

    Suppliers Used

    Line drawings and Parts used

    1 Year On – What have I learned

    2023, Thank you to everybody who has found this blog useful, got in touch or commented, I’ve tried to keep this blog up to date with things I’ve done to the system as you can always ‘tweak’ the system and continue to play with it, especially after the hard graft of fitting it.

    Watering the lawn and tailoring it when and how long is now a simply press of a button and I would defiantly recommend investing the effort as the payback is more time for other things, year on year.

    The system required very little maintenance, blowing the lines out for winter was straightforward, I did however, waste water by leaving the winterisation process a bit to late, meaning instead of using the water in the tank for the lawn, it went to drain as I didn’t want the risk of freezing damage to my tank, even though its insulated.

    Bringing the system back online for a new season was very easy and non of the sprinklers malfunctioned or got stuck in the retracted position.

    The main additions to my system since I initially blogged it are:

    • Rain Sensor to avoid watering when rain has been detected.
    • Tank level detector stops the pump to avoid it running dry if the water level is too low.
    • Dedicated bib tap for my garden hose fed directly off the irrigation pump, this gives me a higher pressure than the mains for washing down or using an impact sprinkler should I need to.

    Tip – Know when your going to use the sprinklers for the last time, isolate the filling water to the break tank in order to leave it empty over winter.

    Tip -Unplug the pump at the same time as draining down just in case it gets activated by accident and is damaged by running dry.

    Tip – A number of my sprinkler body’s had moved from the vertical or sunken since installation due to the ground settling requiring the spade to come out for readjustment.

    I have now hammered in a supporting pin parallel to the sprinkler and fastened with cable ties the body to the pin in a hope that this will keep things level.

    Tip – One of the jobs on the lawn is to aerate and I really struggled finding the sprinkler heads without turning on the system, so I bought a pack of Survey Flags from Amazon and marked where they are and the buried pipe runs, so I know where I have to either avoid or go easy when plunging sharp tines in the ground 🙂 .

    What’s Next?

    I’ve ordered a Venturi Injector from Amazon but they are just as cheap on eBay, the idea is that, with a bit of minor pipe modification at the pump end, I can introduce a water soluble liquid fertiliser into the sprinklers feed water.

    If successful, I will blog how I did it and parts used, so watch this space!

    FAQs

    After deciding on a permanent irrigation system and researching options, two brands were of serious consideration, Hunter and Rainbird, both excellent, however, it was ease of access to documentation, product range and product performance which made me decide on Hunter, specifically the rotating spray head patterns.

    Where are you going to get the water from is the starting point, if you have good water pressure and flow (by measuring it), it may be possible to drive the irrigation system directly from the tap, if so you have saved a lot of money.

    If you have poor water pressure, then you will need somewhere to store the water, (unless you have a well or watercourse), and a pump, as you cannot connect a pump directly to a tap.

    This is the daunting bit, but it is something you can do, I used the Hunter Design Guide, which is full of useful information and the steps to follow.

    I tend to overthink everything and you could throw in a few heads, linked with hose pipe connected to a tap and it might work perfectly, I on the other hand need to work everything out before I commit to effort and spending money.

     

    • Find your water pressure and flow rate.
    • Make a scaled drawing of the area you need to irrigate.
    • Look at manufactures literature and determine the appropriate head pattern and number needed to give overlapping coverage.
    • Total up the water consumption of the heads or the water consumption per zone if you logically can section your lawn.
    • Draw in pipes runs and work out  pipe lengths.
    • Using the calculators in the FAQs or online determine pipe and pump size (if needed).

    With the above info you will now know how much water you need and if you can supply that from a tap, if you can't, consider water storage and how quickly the storage tank will refill as this will be the limiting factor for how long you can water for at a given flow rate.

    I've not touched on how the irrigation system will controlled as I made my own, however, these are readily available and simply send a 24v signal to a solenoid water valve to open or close at predetermining time and sequence of your choosing, some are linked to a mobile app for even more flexibility.

    Pumps need to push a volume of water (output) at pressure, these are measured in Litres per minute (L/m) and Head respectively.

    The pump used in this blog for example has an output of 61 l/min, so theoretically I can supply 19 x MP1000 360 degree rotator heads, with each using 3.18l/min at the same time, obviously this does not take into account sprinkler pipe and fittings friction losses.

    Head relates to the pumps pressure and mine is 46 meters (46m), the easy way to roughly convert this to bar, (a bar is 14.7psi at sea level), is to put a decimal point in-between the number, so 46m, becomes 4.6bar.

    Handy converter for Head pressure is HERE, (SG - Specific Gravity of water is 0)

    Earlier I mentioned pipe friction losses, to put this in perspective my longest run is 37m of 20mm pipe and my pump pressure is 4.6bar, if I had 19 heads taking a total of 61 l/m then the pipe losses would reduce the pressure at the end of the pipe to 2.35bar, well below the pressure required for the heads to operate effectively.

    A pipe friction loss calculator link is HERE.

     

     

    Residential irrigation controller use 24vAC outputs to power water valves, whereas pumps need 230vAC.

    If the controller you choose has a 24vAC output to switch a pump on, you will need a relay to switch the higher voltage and current, these are about £6 on eBay, search for AC24V Coil 8 Pin DIN Rail Electromagnetic Power Relay 10A w Base.

    If the controller doesn't have a pump auxiliary output then you can use an automatic pressure switch, such as the Smart Press.

    What this does is monitor the pressure from the pump, if the pressure drops, such as when the watering valves open, the pump automatically turns on and will continue to run until the watering valve/s close, also this device stops the pump if it runs out of water to protect the pump.

    No, these are bought separately due to the extensive range of spray pattern types, the heads simply screw into the PRS40 body, the other bit you will need is a connection elbow to the base of the body.

    From the solenoid valves to the sprinklers, I used 20mm blue poly MDPE pipe with inserts, the final connection from the poly pipe to the sprinkler body is with 1/2" flexible hose.

    20mm was fine for my setup as its based on how much water it will pass in litres per minute over the total length of pipe at the correct pressure, the longer the pipe, the more pressure is dropped, hence sometimes its easier to go up to 25mm if your not sure.

    See pump size details FAQ for additional details.

    This was an easy decision for me as it removed an unknown, as long as I have a water pressure greater than 2.8bar at the spray head it will work.

    Without the inbuilt pressure reducing valve, I would have to know what the pressure would be in order to select the correct sprinkler head.

    This relates to how high the sprinkler 'pops up' out of the ground, either 4" or 6", the range of the water pattern is greater the higher up it is, but this is based on the design, I manage fine with a 4" lift.

    The main consideration was how long was my aerators tines as I didn't want to damage the pipes at a later date, I buried mine 200mm (8") down which is the length of the trenching shovel I used.

    The pipes are blown empty over winter so I have discounted any freezing risk.

    Since installing my system, I did see a guy on YouTube who used a reciprocal saw to cut this trench and it worked really well as a great idea as long as you are sure you have no buried services.

    The cost for my system was under £900, but I made mistakes, so this blog should save you money in unnecessary purchases, the installation was hard physical work but incredibly rewarding when finished.

    The main benefit is that I can sit back and the lawn will be watered to a consistent standard, every time, allowing me to do other things, like sleep 🙂

    For me it was the line irrigation to planters and drip feeders, the terminology is difficult to understand so I ended up buying lots of things which are now sat in a box, fortunately the bits are relatively inexpensive.

    Bird Bath Auto Water Fill

    start pic

    I bought my bird bath second hand for £10 and have had it for several years, I’ve always hated the colour and topping it up with the watering can every day was getting to be a pain.

    So I thought I would ‘ kill two birds with one stone’, (I know, not the best phase considering the context), anyway, a nice little project in the making.

    My original design ended up way to complex, the plan was to use a Programmable Logic Controller to drain the bowl and refill it everyday, plus some other tweaks such as overfilling the bath to flush out waste and only draining down at night etc.

    I did a relality check and simplified the design to simply fill when the level in the bowl gets low, however, the plumbing manifold was made to allow auto draining if I choose to do it later.

    Current Operation – This is very simple and needs no manual intervention. With the water supply and power on, the liquid level controller keeps the solenoid fill valve closed as long as a circuit is made via the water from the common connector (metal tank connector) to the low level brass stud.

    When the water level drops below the low level stud and the contact to the common connector is missing, the controller, after a short delay, powers the fill solenoid valve and water enters the bird bath, once the water touches the upper contact (high level), the solenoid power is removed and the valve closes.

    How it was made – As the bird bath is made of plastic and the top bowl lifts off the column, I was able to put hardware out of view inside the base.

    First job was to drill and fit the 15mm Tank Connector (£2.79) and a small length of 15mm copper pipe in the top bowl, this will connect to the filling manifold via a push fit coupling, the copper stub will also act as a ‘Common’ connector for the level sensor circuit.

    dish
    dish top
    visio

    The manifold is made of 15mm copper pipe with end fed fittings, the manifold is connected via a 15mm ‘push fit’ connection to the bowl stub, thiis makes maintenance very easy as it all comes apart quickly. The finished pipework is fully lagged.

    inserted manifold

    The liquid level control PCB was off eBay (£3.65 and) fitted neatly inside an IP rated enclosure I already had, in the picture above you can see an earth wire which is soldered to the stub pipe from the bowl and the black cable is a two core to the high and low level stud contacts.

    Studs

    The solenoid is 1/2″ version, 12vDC and connects to the water supply via 15mm tap connectors with fibre washers (£1.50 @ B&Q), I fitted a flywheel diode across the terminals to avoid pitting the PCB relay contacts, the valve was off eBay and cost £4.32.

    The studs are Pan Head 12mm x 4mm brass machine screws commonly used for metal conduit box lids, the studs are positioned at the low level and high level marks. On the underside I have used hot melt glue to secure the sensor connecting wire.

    Finished bb

    Finished project and a new colour, Winsor Green. The water supply to the bird bath is via a hose from an outside tap, the connection at the bird bath is via a hozelok connector with an isolating ball valve, the valve is ‘gagged in’ so the when the solenoid opens, the bath fill is quite slow,

    12vDC to power the circuit board and solenoid is fed from an external IP rated socket with a small plug in PSU.