Note 1

The irrigation system is completely automatic so you can take an extended holiday while the birdbath controller looks after your garden.

Note 2

If water is overflowing at a flow splitter nozzle, there may be pockets of air trapped at the high points in the polypipe. If you can’t remedy the situation by physically removing the high points, you may need to insert an air valve at one or more of the high points by cutting the poylpipe at the high point and inserting a tee with a vertical piece of poylpipe higher than the outlet on the flow splitter.

If there is still a problem after you have removed any trapped air, then you can either

· Use polypipe of greater diameter (for example, change from 13mm polypipe to 19mm polypipe) or

· Raise the level of the flow splitter

Note 3

Head loss along a length of Dot2dot hose is less than 1 cm provided that the hose is less than 5 metres long and the flow rate from the hose is less than 8 litres per metre per hour.

Note 4

The water level in the terracotta bowl will fall due to evaporation and seepage through the porous terracotta into the surrounding coarse sand. During very hot weather the evaporation rate will be much greater and so the time between irrigation intervals will be shorter. On cool overcast days, the evaporation rate will be quite small and so the time between irrigation intervals will be longer. When it rains the terracotta bowl will fill with water and delay the start of the next irrigation interval.

Note 5

The above installation assumed that the 2 litre probe was used. If you use the 1.5 litre probe you need to use Table 4 to determine the measured irrigation volume for each nozzle. Similarly, if you use the 1 litre probe you need to use Table 3 to determine the measured irrigation volume for each nozzle. Whenever you change the probe, the volume of water delivered during the irrigation interval will change. However, your monthly water usage will not change. For example, if you replace the 2 litre probe by the 1 litre probe, you double the irrigation frequency but you halve the volume of water used during the irrigation interval.

Note 6

To deliver water directly to the root zone, the following method for installing Dot2dot hose is recommended. Dig a narrow trench so that the bottom of the trench is just above the root zone (the bottom of the trench can rise and fall according to the depth of the root zone). Fill the trench with coarse washed sand to within about 5 cm of the surface so that when you lay the Dot2dot hose it is horizontal. Cover the Dot2dot hose with mulch, coarse washed sand, or soil. This method will allow you to easily retrieve the Dot2dot hose for reuse without disturbing the soil and plants.

Note 7

Step 6B recommends 10 litres per metre of Dot2dot hose. Depending on the sector, you may wish to vary the volume of water delivered by Dot2dot hose. For example, one sector may require 7 litres per metre and another sector may require 15 litres per metre. Whenever you change the volume of water required by a sector you should change the corresponding flow splitter nozzle accordingly

Installing Measured Irrigation

It is recommended that you view the Youtube video

Measured Irrigation – step by step instructions

Click here to watch

Step 1.                Position the star pickets so that the flow splitter fits neatly between them with the holes in the star pickets facing the flow splitter. Use the nylon string provided to support the flow splitter. Use a spirit level to ensure that flow splitter is horizontal.

Alternatively, a wall bracket is provided so that you can mount the flow splitter on a wall or fence.

Step 2.                Connect the outlet on the water tank to the flow splitter via the pump, the filter and the inlet valve. The outlet on the tank can be up to 1.5 metres lower than the flow splitter.

Step 3.                Connect the pump controller to the pump and connect a 12 volt power supply to the pump controller. A 20 watt solar panel is an ideal power supply and no battery is needed.

Step 4.                Install the birdbath controller in a suitable location near the plants in your garden. The terracotta bowl should be sitting in a bed of coarse washed sand with good drainage away from the bowl, and with the rim of the bowl level with the sand. Place the level sensor on the rim of the bowl.

Step 5.                Assuming that the 2 litre probe is being used, estimate the total volume of water that you would like to use during the irrigation interval assuming that the irrigation frequency is twice a week and that there is no rain. If your estimate is less than 450 litres, then a brown control nozzle is recommended. Otherwise, a yellow control nozzle is recommended. For some irrigation applications other control nozzles may be preferable. Attach the control nozzle to one of the outlets on the flow splitter and use a tube to connect the control nozzle to the terracotta bowl. Note that the nozzle should be open to the atmosphere.

Step 6A.             For each dripper sector install a network of polypipe laterals so that each plant in the sector is less than 50 cm from the nearest piece of polypipe. Each dripper nozzle will deliver a fixed volume of water to a plant (or group of plants) during the irrigation interval. For each dripper nozzle the measured irrigation volume is obtained from Table 5.

For example, if you are using the brown control nozzle, Table 5 tells you that the brown dripper nozzle delivers 2 litres and the olive dripper nozzle delivers 14.4 litres.

For each plant (or group of plants) in the sector select a suitable dripper nozzle and connect the dripper nozzle to the nearest piece of polypipe using a beige connector. Use a length of tube to deliver water from the nozzle to the watering point. Note that the outlets to all dripper nozzles within the sector should be at approximately the same level and open to the atmosphere.

Step 6B.             For each Dot2dot hose sector, allow 10 litres per metre during the irrigation interval. Install Dot2dot hose as laterals or as loops around individual plants. For example, if a plant requires 10 litres of water during the irrigation interval, use a 1 metre loop. When you cut a length of Dot2dot hose, allow an extra 5 cm for connection to the barbed fittings.

Use polypipe and barbed fittings to connect the pieces of Dot2dot hose. For water efficiency, Dot2dot hose should be used only where the water is needed and everywhere else should be polypipe. To minimise head loss in the Dot2dot hose, no part of the Dot2dot hose should be more than 5 metres away from its water supply via the polypipe. It is preferable that the Dot2dot hose is submulch or subsurface to reduce evaporation losses.

Within each Dot2dot hose sector, the hose should be at approximately the same level throughout the sector.

Step 7.                For each sector add up the total volume of water required by the sector during the irrigation interval. Use Table 5 to determine a suitable combination of flow splitter nozzles to deliver the required volume of water. Attach the nozzle(s) to outlet(s) on the flow splitter and connect the nozzle(s) to the sector. Note than all nozzles should be open to the atmosphere.

Step 8.                Turn on the power to the pump and adjust the inlet valve until the water level in the flow splitter stabilises just below the inlet.

Step 9.                Use a pressure monitor tube to check the water pressure at any point in any sector to be confident that everything is working according to your requirements. Within each sector the head of water should be approximately the same throughout the sector.

For each dripper sector, the head of water should be approximately the same as the head of water if the flow splitter. Measure the head of water above the nozzle outlet.

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Address: 5/50 Harvey St, Woodville Park,                  South Australia 5011        

Phone: (08) 8244 0071

Mobile: 0403 935 277

Email: bomodei@dot2dot.com.au

Measured Irrigation

 

Measured Irrigation Video

step by step instructions

Click here to watch

6 min 41 sec