How to fix water tank losing pressure when hose is attached?

[cassius23]

when opening the valve the pressure is stronger than any other tap but when I attach the hose fitting it loses that pressure and and comes out slowly 

[EricL]

Hello @cassius23 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your water tank.

The reason your garden hose has lower pressure than the tap on your water tank is likely due to a combination of factors that restrict water flow once it enters the hose. While the pressure at the tap is generated by gravity (the height of the water above the tap), that pressure is often enough for good flow at the outlet but becomes less effective when faced with resistance inside a hose. 

One common issue is the diameter of the hose—narrow hoses (like standard 12mm ones) significantly restrict the flow of water compared to wider hoses. The length of the hose also matters, as longer hoses cause more friction loss inside the pipe, which further reduces pressure. In addition, any kinks, bends, or obstructions inside the hose will slow the flow, even if the tank is full. Hose fittings, connectors, or spray attachments can also be culprits; if they have small openings or are partially blocked with debris or mineral build-up, they act like a bottleneck. 

Lastly, if you’re using the hose to water areas that are uphill from the tank, gravity works against you and reduces pressure further. All of these small resistances add up and are much more noticeable in a hose than they are at the tap itself, where the water is exiting freely. Making sure the hose is wide enough, as short as practical, free of kinks, and fitted with high-flow connectors can help improve performance. 

For better flow, I suggest removing your garden hose gun and garden hose fitting at the end and observe its flow with no impediments. Otherwise, my only other recommendation is to invest in a pressure pump that you can attach to your water tank.

If you need further assistance, please let us know.

Eric

[AlanM52]

As mentioned that is a gravity feed system and the suggestion is a pressure pump.

More specifically you need a Peripheral Water Pump like this one:

https://tinyurl.com/y45hxrk5

They are smaller/cheaper and should be adequate for your needs.

You will need irrigation fittings, the standard water tank outlet size is typically 1 inch (25mm) for tanks up to 10,000 liters.

That pump also has a 25mm inlet. The pump outlet will need something like a elbow with reducer to garden hose snap-on connector.

Go for a stroll through the Bunnings irrigation section and see what you can find.

When doing your own searching use 'Peripheral Water Pump' as you search criteria.

Good luck.

[MitchellMc]

Great advice from @AlanM52 there @cassius23.

If you are looking for a pump in-store then I'd suggest something along the lines of a Ozito 800W Constant Pressure Pump. It has a flow switch that activates the pump when needed. Ideally, it can also be hooked up to a tap as shown below.

Mitchell

[AlanM52]

Sorry... I forgot to mention that one.

[MitchellMc]

That's all good @AlanM52! We have so many products that I forget about them. I just thought it might be a convenient option.

Mitchell

[cassius23]

It looks like there used to be a pump against the wall that has been removed that has other outlets there, maybe connected to flush toilets. Would I need a specific pump to hook this back up and still use for watering garden? thanks 

[MitchellMc]

Hi @cassius23,

You'd likely need a plumber to assess your needs and recommend an appropriate pump for your installation. Perhaps something like the ClayTech Ecoboost 3+ Constant Pressure Pump would be more suitable for watering the garden and filling internal toilets.

Please let me know if you have any questions.

Mitchell

[cassius23]

Thanks for the feedback