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Hello Everyone,
I currently have a 1000L rainwater tank in the back garden, which is only used to supply one toilet using an automatic outdoor pump.
This seems a bit of a waste. My plan would be to somehow use this pump to also supply this rainwater to the front of the house (where there is currently no water supply) to water the garden/wash the car.
As can hopefully be seen from the attached diagram, my plan is to Tee off the pump outlet, run a pipe under a patio (trench and protect with sand), through a garden bed and probably use a Tap Post so I can use a hose. Distance is approx. 50 meters round the side of the house.
I would also like the option to possibly use this pipe to install Drip Irrigation along the pipe at the garden bed. This would, naturally, only water the garden when the pump is activated. I could either manually run the pump to water the garden or simply allow it to happen as a side effect of using the toilet or front-of-house hose.
So my questions are as follows:
1. Would it be possible to use standard Poly Pipe? Or could I use a 'standard' garden hose?
2. Would there be water pressure issues? The system would be 'closed' so I don't think so.
3. What have I missed?!
Many Thanks in advance.
Welcome to the Bunnings Workshop community @NotHarryPotter. It's wonderful to have you join us, and many thanks for your question about plumbing a garden tap.
Having the tap connected sounds entirely possible. First, you'll need to check with your local council to find out whether a registered plumber is required for this work.
You'll need to determine whether the current pump is designed to cope with your needs and additional connection. If its only purpose was to fill the toilet periodically, it might not be capable of providing the flow required to use as a garden tap to water your yard.
Due to the drip irrigation, the system will be open and constantly lose pressure. I would have thought this would cause the pressure switch to activate and the pump to turn on and off constantly. I believe these pumps work as when the pressure drops in the line, they switch on and then turn off when they receive back pressure. For instance, let's say that the pump switches on below 95psi and off at 100psi. It will build pressure in the line to 100psi and turn off. Since the drippers release a slow flow of water, the pressure in the line will drop over, say, 30secs and hit 95psi. The pump will then turn back on to hit the 100psi mark again. This process will go on and on, and that's really not good for the pump.
For an irrigation system, you'd require a transfer pump that provides constant pressure.
You could likely run irrigation, but that should be done after the tap, and there would need to be enough sprinkles/drippers to cause the pump to run constantly and not switch on and off all the time. You'd need to isolate the irrigation system at the tap when not in use or have it on a timer. Once again, you'll need to check the pump's specs to ensure it's capable of running constantly under these conditions.
Please let me know if you have any questions.
Mitchell
Hi Mitchell,
Many Thanks for your speedy and in-depth response.
Regarding the pump constantly wanting to recharge once the drippers were empty/below pressure; I forgot to add a non-return valve to my diagram which I hoped would be all that was needed to maintain pressure in the first half of the system and prevent the constant priming. The idea being the drippers would remain in stasis until the pump would run - either manually switched on or activated via the toilet flush or new tap use.
I managed to find details of the pump itself. It's a Bianco Pumpz model BIA-INOXG60MPCX.
A quick Google indicates a flow rate of 32psi using 1" pipe (input/output). If the average house water pressure is @50psi, I think it would struggle to provide a decent hose spray, especially after 50m. The reducing of the system to 3/4" through the fittings may help, but I doubt it would make enough difference. The pressure loss in having the drippers run while also running the tap would probably render it useless anyway!
I think (with your help) I've convinced myself to go back to the drawing board..
Thanks again.
I should have thought of using a non-return valve, @NotHarryPotter. That would likely work.
I'd imagine you'd still get a decent spray from the hose, and I don't believe there would be a significant reduction of flow from the drippers as they have a very low rate.
Mitchell
