It's officially summer and we have many friends and relatives coming to stay at the property for the first week of July. In a previous post, Off-Grid: Berkey Water Filter and a Full 1000 Gallon Cistern of Drinking Water, I mentioned that twice a week I lawn tractor and trailer transport a load of containers with drinking and cooking water from the 1000 gallon water cistern at the top of the valley hillside - to the cabin that is halfway down the valley hillside. @steven-patrick suggested that I run a hose. I replied that most of the hose running I would be doing this summer would be for the garden rows. There hasn't been much rain this summer. My wife recently expressed her desire to have the hot tub filled with water so the guests and ourselves can use it as a dipping pool to cool off - so I ran a 300 foot garden hose from the cistern to fill the 250 gallon hot tub.

Priming the Siphon Hose with a Bilge Pump

Instead running the bilge pump the whole time, I ran it for 2 minutes. Just long enough for the water in the hose to start emptying into the rocket stove boiler - starting a siphon.

What is a Siphon?

Water and other liquids can be moved to a lower destination with the siphon method using a hose or tube. First the hose is filled with water - primed. One end of the hose is quickly placed outside of the container - lower than the other end of the hose that is still in the water in the container.

As the water empties out of the lower end of the hose, outside of the container, it creates a suction or siphon effect that draws the water from the container. The end of the hose in the container must remain in the water and higher than the other end of the hose - or the siphon effect will be broken and the water will stop flowing.

The Bilge Pump Setup

In the picture below you can see the 12 volt bilge pump. Bilge pumps are for quickly moving water from one place to another. This bilge pump is rated to move 2000 gallons of water per hour. You can see the white hose going from the bilge pump to the green hose that runs 300 feet down the hill to the rocket stove boiler that will be used to preheat the water before it exits the boiler spigot in a hose - down to the hot tub. The white hose is actually two hoses connected with a black push on connector.

In the picture above you can also see the 12 volt male connector going to the bilge pump.

12 Volt Accessory Jack for Lawn Tractor

In the picture below you can see how I attached a 12 volt female connector to the lawn tractor's 12 volt battery.

12 Volt Bilge Pump in Cistern to Prime Siphon Hose

In the picture below you can see the bilge pump sunk into the cistern, well below the water line. It is plugged into the tractor's 12 volt power supply and pumping water to the green hose.

Removing the Bilge Pump

After the bilge pump runs for a couple minutes, long enough for the water to get to it's rocket stove boiler destination, the white hose is then split into two at the black connector with the end connected to the green siphon hose being fed to the bottom of the cistern and the end connected to the bilge pump being pulled out of the cistern with the bilge pump. The water will continue to flow down to the boiler - the siphon has been started.

In the picture above you can see the cistern lid propped open with the siphon hose coming out of it. After the hot tub has been filled the hose will be removed and the cistern lid safely sealed.

Watch the 300 ft Hose Run Video: Back Acres: 300ft Siphon from Cistern to Hot Tub

Siphon Hose Destination - the Rocket Stove Boiler

In the picture below you can see the destination of the siphon hose - the rocket stove boiler.

In the picture below you can see the water flowing into the boiler. If a spigot is added and turned off - or the hose is pinched - as long as the top end of the hose in the cistern remains under water, the siphon hose will remain primed (full of water) and the flow can be turned back on by un-pinching the hose or turning the spigot on - without using the bilge pump. Think of a straw full of water and pinched at the top - the water remains in the straw.

In the picture above you can see the rocket stove burn chamber fire that is preheating the water in the boiler for the hot tub. The boiler has a spigot on the bottom with a metal braided dishwasher hose attached that feeds the cabin's outdoor hot water line. A previous post of mine discusses the rocket stove boiler and outdoor hot water line with outdoor shower in more detail: Off-Grid: Rebuilding the Rocket Stove Boiler and Connecting Outdoor Plumbing for Spring Showers.

Final Destination: the Hot Tub

In the picture below you can see the green hose from the outdoor hot water line going to the hot tub.

The hot tub continued to fill...

Six hours later the hot tub was full. The cistern lid was safely sealed after the siphon hose was pulled out. The heater for the hot tub won't be turned on, this tub is for cooling off this summer.

Have a great day!