garden irrigation

I'm wanting to get a 5 or 6 hp gasoline water pump and a few oscillating rainbird sprinkler heads to water my garden with.....the sad thing is, I don't know the in's and out's, the do's and don'ts of how to go about it. I want the set up to be simple and easy to use and not expensive to build. I've got a 16,000 gallon cistern as a water source and only intend to use irrigation for the few dry spells that occur through the summer. My garden is about half an acre in size.

Surely somebody in the audience has something similar that they are using or can supply some advice.....pictures would be greatly appreciated.

How quickly do you want to water it and how much water do you want to put on. 16000 gallons is 4960 cu ft. On a half acre of ground, that"s ~ 2.7 inches of water if you pump the cistern dry and distibute it over the entire half acre.

Aluminum handlines with sprinlers will put out ( for example, 5/32" nozzle @40"psi will put out~ 4.6 gpm and with 40ftx40 ft spacing), will put out about 0.28 inches of water per hour. Knowing the dimensions of your garden, figure out how many 40 ft pipes will go lengthe wise on your garden and how many 40 ft widths will gover the garden.Thet will determine the number of sprinkler heads you"ll need and how may moves you"ll have to make. The number of heads, the pressure at the nozzles and the nozzle size will size your pump flow rate. The pump pressure will have to be higher than the pressure of the nozzle to account for line pressure losses in the delivery system. So that pressure, the flowrate and the pump efficiency will size the motor.
That"s a synopsis on how I would approach your problem.

I have a water system built for my garden. Because I have a natural pond on the farm I have a tanker set up. A 4-5 HP pump is way too much for the sprinklers you are talking about.



I had to go with a smaller pump the big one is use to fill the tank and the samll one to water with.

Rick

Big pump

Interesting comments thus far!

OK, as for the garden size it is about 125" long and 75' wide. I sorta figured one run of sprinklers down the middle working in a full circle would pretty well cover everything needing water the most, and those three heads in-line should overlap down the length of the garden. My initial thoughts were to use 1.25" black poly pipe for the mainline and insert tees and reducers for my uprights to mount the sprinkler heads on.

I didn't plan on trying equal a downpour (2+ inches) at a time! I figured I could run a tank of gas through the pump...about a gallon, which supposedly gives about 3 hour run time. That ought to be enough to give everything a good drink and if not, then I can run another tank through it.

I'm looking at the Harbor Freight 6 horse pump with 2" intake and exhaust ports and I think it is advertised at 35-40 psi and 150 GPM...using the 2" line......which I figure should deliver plenty of flow for the 3 heads even though the delivery line is reduced in diameter. As for the pump being too big, if that's the case, I'd think adjusting the throttle to a happy spot would regulate the output easy enough. These are just my thoughts on providing a simple solution. Maybe my logic is entirely wrong.

I have looked at the pumps sold at HF, Lowe's and TSC and other than the paint...they appear identical...they're all made in China and have Honda clone engines on them.

Have you gave any thoughts on using a electric pump... Far as the pipe I got all the 1" 1/4 I wanted free on the local swap shop...

http://ytforums.ytmag.com/viewtopic.php?t=779872&highlight=pipe

I have a horse and a haft submersible pump in the pond,,, irrigation Pipe is ran all over Ireland and haft of ell... gives all irrigation needed...

My experience when I tried it was I used an awful lot of gas for the amount of water delivered...looked impressive while running though. Some of the inefficiency was likely using garden hoses and bargain store sprinklers...still my gut says it was a fundamental mismatch between too much pump and too little nozzle that was most of the inefficiency.

The very generic rule of thumb is 1" of rain per week, which works out to 5/8ths of a gallon per square foot. Your mileage may vary based on soil, climate, mulching, cultivation, and plant life stages...but it seems to be a good point to start planning and then adjust based on your observations from there.

If I was to use the gas pump again, I'd redesign the system to use a 300 gallon tote tank (cheap to buy) and drip lines. Specifically drip lines which are hoses/plastic pipe with pin holes...soaker hoses use a membrane that require more pressure then a tote tank on the ground could provide.

I have a 1600 s.f. garden, so if I ran lines around the garden that would make 5 zones, which could be controlled by a valve or just which one I thread on.

I'd only have to run the pump 3, 4 minutes to fill the tote at high volume/low pressure -- that's a total of maybe 20 minutes a week. Takes a lot longer running higher pressures / lower volume to feed sprinkler heads, and you'd need enough sprinkler heads to match the pump capacity.

(For now, I'm working from home and use a diverter valve off my sump pump which runs regularly anyways. Not enough pressure to run a sprinkler, but I just go out every 3-4 hours and move the open end of the hose to flood another section.)

Have you considered soaker hoses and gravity from the tank?

yes, I considered an electric submersible until I priced one....wow! Without a doubt, much cheaper to operate, no noise, etc., etc. Back in day before we got city water out here in the county, I had 2 wells and bought about 4 pumps over 20 odd years. By and by, they'd suck so much sand and debris through the pump stages...which were plastic, that they'd self destruct. I was pumping out of a 120 ft. deep 6" well and used 3/4 hp pumps and they worked fine. A 1.5 hp pushing little no more head than out of a cistern or pond would be a beast. Because of the grief I had pulling bad pumps out of those wells....I'm loathe to buy a used submersible pump. A new 3/4 horse submersible is close to $400 now. The gas pump at HF is currently $149. Not only that, it is totally portable in case I should need it elsewhere.

I'd go the soaker route. You'll have less waste, and evaporation. Also better, as wet leaves can make plants more susceptable to disease. One of my garden spots is about 130' square, rows are hilled, and spaced to allow it to be worked with my 8N. I water next to the hills, in the furrow the hiller made. Fortunately, the ground has a gentle slope down the hilled rows. Pump out of the tank with a roller pump on one end of the row, and it flows down to the other end. I don't have a water source at that spot yet, have to haul it about 1 mile. Works pretty good for me. We've got squash, green beans, cukes, okra, and starting a blackberry patch this year. Prepping another 130' square patch adjacent to the current one. We'll fall crop more beans, turnips, and cabbage. Po folks got po ways. Mark

Mark,

My garden is 40' by 100', about a tenth of an acre so using the porous soaker hose method may be too much manual effort for your application. However, the advantage to the soaker hose is I can water only the plants in the row and the soil between the row stays dry - less weeds to deal with. I use a 100' hose with a 3/32" diameter restrictor disc installed between the soaker hose and the feed hose from the house water pump. With the restrictor in place the soaker hose does not spray but simply drips and the well pump only cycles every 20 minutes or so. If I lay the soaker hose along side the sweet corn I can water a strip of soil 8" wide and it is wet 4" to 6" deep. I also have some soaker hose cut to shorter lengths and use a 1/16" diameter restrictor for those. Saves a lot of water and starves the weeds.

All my hoses have weighted ends that I made from old hose fittings I filled with old lead solder. This seals the fitting and makes it heavy to hold the hose in place without curling around.

(quoted from post at 01:06:11 07/05/11) yes, I considered an electric submersible until I priced one....wow! Without a doubt, much cheaper to operate, no noise, etc., etc. Back in day before we got city water out here in the county, I had 2 wells and bought about 4 pumps over 20 odd years. By and by, they'd suck so much sand and debris through the pump stages...which were plastic, that they'd self destruct. I was pumping out of a 120 ft. deep 6" well and used 3/4 hp pumps and they worked fine. A 1.5 hp pushing little no more head than out of a cistern or pond would be a beast. Because of the grief I had pulling bad pumps out of those wells....I'm loathe to buy a used submersible pump. A new 3/4 horse submersible is close to $400 now. The gas pump at HF is currently $149. Not only that, it is totally portable in case I should need it elsewhere.

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You can also get those gas power units in electric... I know sever folks that use'em and like'em...

I'm awful dissappointed in you tanker. I thought you'd have a nice old M456 water buffalo, desert camo, nd tires, something like that.

LOL Tony......never even thought of that, water buff would double my water supply! Nope I got the tank setup at auction. It was set up with the big gas pump (Honda) for filling and a tractor mounted pump for the sprikler heads. For where I have to get the water from I have to use the IH M, my Ford 8N is just to lite. The M uses way too much gas even at idle to pump water with. The guy who buit the unit had a JD compact utility diesel. So I added the samll pump and it works well. I've got less that 600 invested in it.

Rick

Is there only one crop in the garden? If more than one crop you will be wanting one dry for harvesting while the rest is drying up wanting that water. Havent been able to get a garden out for a few years but last year I used soaker hose andfor each pair of rows-soaker hose I connected then together with old auto washer fill hoses (3-5'Long) with a valve going off to each soaker line and they were hooked to the well pump and I could just turn on the hose to the part that needed it with no two crops needing the water at the same time. Sprinklers that I tried using before wasted way too much water and you set them where they would cover the area you wanted and 15 minuts the wind would change and you would not be getting any water on the garden where you wanted it. And with those sprinklers before you were halfway done watering your garden you will be out of water, you will waste an inch for every inch that gets used. If I can get back to a garden it will be those soaker hoses and if I want it dry to pull radishes I can do that while giving the tomatos a good drink. Not have to pull those radishes standing in the mud from the water that did not get on those tomatoes that are dry..

(quoted from post at 13:40:33 07/05/11) Is there only one crop in the garden? If more than one crop you will be wanting one dry for harvesting while the rest is drying up wanting that water. Havent been able to get a garden out for a few years but last year I used soaker hose andfor each pair of rows-soaker hose I connected then together with old auto washer fill hoses (3-5'Long) with a valve going off to each soaker line and they were hooked to the well pump and I could just turn on the hose to the part that needed it with no two crops needing the water at the same time. Sprinklers that I tried using before wasted way too much water and you set them where they would cover the area you wanted and 15 minuts the wind would change and you would not be getting any water on the garden where you wanted it. And with those sprinklers before you were halfway done watering your garden you will be out of water, you will waste an inch for every inch that gets used. If I can get back to a garden it will be those soaker hoses and if I want it dry to pull radishes I can do that while giving the tomatos a good drink. Not have to pull those radishes standing in the mud from the water that did not get on those tomatoes that are dry..

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I have about 3 acres in garden this year. About 2 acres are too far from the house to get water out there and I'd have to have a drilled well about 100 feet or so. So I waste a little water. Only other option would be to till up some of the pasture and that's not about to happen. If anything I need more pasture not less. LOL as far as running out of water it takes about 10 min to get a refill. And it takes 6 fills to water once. But being semi retired allows me the luxery of time. 10 min to fill, about 30 min to water one tank full so about 3 hours to water. I can do that once or twice a week if we have no rain. Not worried about today, had about 2 inches last night. Add in that with back and knee problems I'm not about to try laying and picking up seeper hoses between cultivating.

Rick

In Marks situation the cystern has to be refilled at some time from rain that falls and puting on that much water the cystern would be empty before the next rain. And On my hoses I lay them once and then cover with plastic and plant thru the plastic, where I was doing that with the hoses I was not cultivating, no need to.