[Guest]

I have a 1,550-gallon cistern full of water and a 2,000 row-foot drip irrigation system. It gets very hot here in Central TX and my wife and I have been planning ahead for the last couple of years so we could stop watering our 1-acre garden by hand, hose, bucket and gallon jug.

Only problem is, the water pressure in the cistern is not sufficient to push the water through the drip system. It is roughly 150 feet from the cistern's faucet to our garden, where a garden hose meets the 1/2" poly tubing that runs up a slight slope (I don't know how to estimate it, but it's slight) through our garden. Anticipating this potential problem, I set up a main line running up the garden (about 100 feet) and four trunks intersecting it and running perpendicular to it for a distance of around 40 feet, each with an on/off valve and lengths of 1/4" laser-drilled dripline running no further than 15 feet from the trunk, to ensure that water pressure could be more or less maintained. I also ran a pair of 1/2" soaker hose tracks, each about 100 feet, with their own shutoff valves, to water our melon patch. Now we've discovered that the pressure is not sufficient to get water to the top of the garden, even if all other valves are shut, and that the soaker hose won't do much at all, even with the same precaution.

At the end of the summer, when the cistern is empty, I will probably do what I should have done in the first place, and raise it up on a platform 2-3' off the ground. In the meantime, I'd like to come up with some way to pump the water. We are poor and cannot afford an expensive pump.

So far, I have one idea. We have an old washing machine with what I assume is a working pump. I know I could adapt the inlet hose to a garden hose and run water from the cistern through this pump, then feed it into another garden hose and out into the garden. My question is this: Would the water pressure be sufficient? Too high? Would I run into other problems? The pump, being in a washing machine, is activated by a timer that runs the cycles of the washer. Would it be beyond the reach of a smart guy who is no electrician to disconnect this timing system and add a manual switch in its place? I figured I could leave that whole system inside the washer (they are very difficult to take apart) and modify the case to be a sort of "pumphouse" by adding weatherproofing. Is this idea just crazy enough to work, or just plain crazy?

Are there other factors I am not considering? Any other cheap water-pumping ideas? If we did suck it up and buy a pump, how weak/powerful would it need to be? The last thing I'd like to do is blow my driplines apart.

Thanks for any guidance or advice.

 

[Guest]

Sounds like you spent some money on the irrigation system already, can probably find a few bucks for a good cheap pump to do the job & not have to spend about as much on switches, tubing, fittings, and the like to rig up the machine?

I'm not sure how much water you are trying to pump, or what pressure you want, but I'd think you can find pumps pretty cheap.

Raising your cistern 2' will add 1 psi to it.

--->Paul

 

[moopups]

Water gains about 43 psi per 100 feet hight, what presure is you drip system designed to operate at? Posabibly an accumulation tank at the lowest point equiped with a compressed air 'topping off' switch? There are available very sensitive pressure switches, sealing a cistern to handle compressed air sound fruitless. As for washing machine pumps I have no idea about it. Do you have enought drop elsewhere to install a hydrostatic ram? Check the archives under the water catagory for more info.

 

[HermitJohn]

These are rather light duty pump, made to drain water from washer tub to sewer pipe. Modern washers, these are even made mostly of plastic.

My only experience with them was using one for an outdoor shower when I was living without electric in MI. (belt driven off lawn mower engine that I also salvaged out of dump) There was pretty good pressure. Remember though that it only got used say 15 min at a time. How it would hold up under more frequent or constant use, I dont know. It was also older model made of aluminum, not plastic kind used today.

A small new electric pump isnt all that expensive, but not going to hurt to experiment either if your money is worth more than your time or if you are just curious.

 

[Blu3duk]

you might think about finding an old RV that is beingtorn apart and gettingthe water pump fromit, already has a switch, and probably be able to use 12 volt or 110 as well with it.

washingmachines aare easy to tear apart nd the pumps are acessable pretty much on all makes and models..... some are in front others in back, the cycles can be circumvented by just using a straight motor and forgeting about the washing cycles and controls.

For under 430 you can get a vane type bronze pump that hooks into your drill and runs inlet and outlet for a garden hose already... adjust for a regular always on motor and you will be pumping water for under $50.

I would not hesitate to try the washing machine pump, it is most certainly a vane pump, and it would be a starting point, if it dont work you are only out the time and a few parts.

William

 

[Cyngbaeld]

Washing machine pumps burn out really easily because they weren't intended for what you need. Might I suggest you pick up a submersible sump pump at the hardware store? Some of them can hook directly to a garden hose. Then you just drop it into the cistern. They are usually ll0 v ac. The RV pump is a good idea if you have 12v hooked up. Otherwise the ac would be easier. They are usually less than 100$. Think the last one I bought to irrigate with was less than 75$, but it has been awhile.

 

[stonefly71]

For 230.00 bucks at tractor supply you can get a trash pump and hook it up and that will be all you will ever need. Mine is a 3.5 or 5 hp motop with a pacer pump.

 

[owhn]

from what little i've read on this to be able to comment:

1. You need about 10 psi to deliver the water through the piping system.
2. This is in addition to that "slight slope ".

to raise it to 10 psi, the water lever (and by inference base of the cistern) need to be in excess of 20 feet high. thats in excess of 12,000 pounds suspended 20 feet high.

So basically, can you buy a pump cheaper than suspending the HEAVY tank?

Also, is a cistern that size even remotely adequate to your gardens needs?
Seems like lots of irrigation piping and NO water????


owhn

 

[owhn]

just to add.. since you have the system installed.. the best way to find JUST how high to raise the cister is empirical...

First fill the system and raise a supply hose it untill you get SOME flow.....
THEN you might take a gallon plastic milk jug a tape a hose section to it after it is full of water ..... and connect IT to a funnel attached to to the supply hose ... and time the flow at increasing elevations.... until you find the height you need for the system


(make sure there is a hole in the normal bottom of the gallon jug to prevent a vacuum lock)

also will help in sizing your pump.... if you go that way


owhn

BTW What flow rate do you need. gallons per day?

 

[agmantoo]

If you have a pressure vessel such as a water storage tank you could fill the tank with water then using a small cheap air compressor charge the tank and the air would push the water thru your irrigation system at whatever pressure you set the compressor to pump.