Gas powered water pump questions

[plowhog]

First of all, sorry to learn of your drought conditions. I'm dealing with the same in CA-- creating similar although different questions and problems.

I have been watering from our well sparingly to keep things alive but I don't want to do that too much.

Q- why avoid using the well? Using it seems a lot simpler than hauling or pumping water from 500 feet away? Are you worried about maybe pumping it dry, and if so, do you know the well recharge rate?

I have a decent size pond with relatively clean water and it has never gone dry.

Q- how big is the pond, and could you theoretically make it go dry if you start taking a lot of water from it?

repurpose a 275 gallon water tank that I can put on my trailer, pump that full in just a minute or two, and then haul to the gardens where I can use a small electric pump to distribute it. Obviously less work overall but more time consuming going back and forth.

Q- I tried doing this to irrigate our recently planted apple trees this year. Although I hauled the 275 gallon tank and expected to use it with gravity flow to the trees, which turned out to be quite stupid given that it took forever to gravity flow the water out of the tank through a hose. Yes this involves a lot of effort to fill, haul, and empty the tank. Even if you approach it more wisely than I did.

I am pretty confident that I'd still be left with way more pressure than I currently have off of our well head, which is only doing like 5 GPM. If I run thru the house I get better pressure because I'm coming thru the pressure tank first, but I bet it still not more than 10 GPM. At that pressure, three sprinklers will already cover the garden.

The above generates a lot of questions:
- Why do you believe you get more GPM "coming through the pressure tank?" If i read this correctly, the "pressure tank" is your bladder tank that is part of the well system. It's purpose is not to increase pressure; in fact, it can't do that. Its purpose is to limit rapid cycling of the well pump, so it doesn't constantly turn on and off. If you don't "run thru the house" for more pressure, where is that other connection? A yard hose bib?
- fyi, pressure is rated in PSI, and volume is rated in GPM. They are different things, although related. You might consider adding some inexpensive pressure (PSI) gauges to your system. Most likely there is already one right at your well head or near your pressure tank. You could probably go look at it now and see the exact pressure of your system. You can also get inexpensive PSI gauges that screw onto hose bibs. Then you could compare PSI at your well (the source) and at the garden (or nearby hose bib) to see if they are similar or different.
- fyi your well pump likely has a "cut-in" and "cut-out" pressure setting. Commonly, a well pump will cut in at 40psi, and cut out at 60psi.
- I'm unclear about using sprinklers to water your garden. How large (in dimensions) is your garden, and is this how you normally water it? (A few photos would help ...) Knowing this answer is kind of key as typical sprinklers are going to require reasonable / good pressure, and gpm, whereas if you can gravity flow water or use lower PSI drip irrigation then that opens some more options.

Apologies for so many questions, but the more info at hand the better answers to provide. Again, I sympathize with the problems induced by drought and I have been fighting the same battles as you. This year is a significant drought. Not too long ago we have 4 consecutive years of drought.

 

[hartmacw]

I run a 1 1/2 Honda pressure pump into 1 1/2 poly pipe around the perimeter of my property with tees and hose bibs strategically placed around the yard. Works perfectly.

Thank you all, these replies have been super helpful. So now I have another newbie question. Would I have to run the same size discharge pipe/hose the whole way (500') and put hose bibs in where I need them or can I neck down to a 3/4" garden hose off of the discharge pipe? Would that put too much pressure on the pump?

 

[CobyRupert]

Can you read and understand pump curve charts? The pump you’re considering should have one.
I’ve never got into them, but my understanding is they will tell you the balance of gpm, pressure and horsepower for a certain amount of head (lift).
People who sell pumps should understand them.

 

[hartmacw]

First of all, sorry to learn of your drought conditions. I'm dealing with the same in CA-- creating similar although different questions and problems.


Q- why avoid using the well? Using it seems a lot simpler than hauling or pumping water from 500 feet away? Are you worried about maybe pumping it dry, and if so, do you know the well recharge rate?


Q- how big is the pond, and could you theoretically make it go dry if you start taking a lot of water from it?



Q- I tried doing this to irrigate our recently planted apple trees this year. Although I hauled the 275 gallon tank and expected to use it with gravity flow to the trees, which turned out to be quite stupid given that it took forever to gravity flow the water out of the tank through a hose. Yes this involves a lot of effort to fill, haul, and empty the tank. Even if you approach it more wisely than I did.


The above generates a lot of questions:
- Why do you believe you get more GPM "coming through the pressure tank?" If i read this correctly, the "pressure tank" is your bladder tank that is part of the well system. It's purpose is not to increase pressure; in fact, it can't do that. Its purpose is to limit rapid cycling of the well pump, so it doesn't constantly turn on and off. If you don't "run thru the house" for more pressure, where is that other connection? A yard hose bib?
- fyi, pressure is rated in PSI, and volume is rated in GPM. They are different things, although related. You might consider adding some inexpensive pressure (PSI) gauges to your system. Most likely there is already one right at your well head or near your pressure tank. You could probably go look at it now and see the exact pressure of your system. You can also get inexpensive PSI gauges that screw onto hose bibs. Then you could compare PSI at your well (the source) and at the garden (or nearby hose bib) to see if they are similar or different.
- fyi your well pump likely has a "cut-in" and "cut-out" pressure setting. Commonly, a well pump will cut in at 40psi, and cut out at 60psi.
- I'm unclear about using sprinklers to water your garden. How large (in dimensions) is your garden, and is this how you normally water it? (A few photos would help ...) Knowing this answer is kind of key as typical sprinklers are going to require reasonable / good pressure, and gpm, whereas if you can gravity flow water or use lower PSI drip irrigation then that opens some more options.

Apologies for so many questions, but the more info at hand the better answers to provide. Again, I sympathize with the problems induced by drought and I have been fighting the same battles as you. This year is a significant drought. Not too long ago we have 4 consecutive years of drought.

Thanks, as you can see I don't know much about this stuff - and living out in the country for so long I feel dumb that I don't know . Anyway, I probably should have just left out the part about watering off the well because I really just wanted to investigate what it would take to utilize a pond that never dries up. What I really meant to say is that for example, if I fill a bucket at the house it takes half as long to fill it as it does from the hydrant at the well (before it goes into the house). Now maybe that's indicative of some other problem. Our well is about 225' deep and the pump is circa 1980's we believe. We don't know what size pump is down there since we bought this place 6 years ago. If I hook my sprinklers up to the hydrant, I get less coverage on the gardens than I do running thru the house. I don't know why, that's just what it is. And, yes, while we've never had water problems I was concerned about running it low or dry during a drought although I have no idea how unlikely that may be. I have pond that never goes dry though

OK, so I have two gardens and I have two 360 degree rotating rainbird sprinklers set about a third of the way in the middle in each one about 6' high on a t-post. That will currently cover the gardens off of the house with some overlap in the middle of the garden. I've been running one for a while and then switch to the other. I only run one at a time. One garden is 80'X40' and one the other is 60'x30'. I'm just investigating what it would take to irrigate those two spaces from the pond which is approx. 500' away.

 

[plowhog]

I don't know your system but it seems backwards that a hydrant near the well has less volume than at the house.

Q- do you have a hose bib directly connected to the well equipment, or is the hydrant the closest "tap" to get water from?

Also, you might consider piping and pumping water (using a gas pump) from the pond to a holding tank near the house (poly tank, etc. maybe 2,000 gallons +/-.) That way you can run your gas pump for a short time, maybe once a day or every few days to fill the poly tank.

The use an electric pump (at the poly tank site) to pressurize the water out of the poly tank for the sprinklers. Yes I know that adds some complexity, but it also might simplify things. Otherwise, you would have to be running the gas pump to operate sprinklers, pushing water a long ways from the pond through pipes out sprinkler heads. I'll think more on your issue but it is one other possible route to consider.

Check with your county or local water officials-- you may be able to retrieve records on your well that were recorded when it was installed. Such as depth, gpm, etc. Also, there is most likely a pump control box at your well-- it may have a placard on it with your pump hp rating.

 

[EddieWalker]

If you go with a gasoline powered pump, you will have to put the pump next to the pond. Your suction hose is probably only going to be 10 feet long. Longer will cost more money, but the amount of water you will be able to pull out of the pump will decrease with a longer suction pipe. This is a rigid pipe that will not collapse when the pump is sucking the water from the pond. Your discharge pipe can be just about anything. For your length of run, Schedule 40 PVC should be good.

The engine is the most important consideration when buying a pump. I would only buy Honda. Everything else is going to give you issues before the Honda will. Other then the cost and time you will spend keeping it fueled, changing the oil will become a constant issue too. Once they run for so many hours, the oil has to be changes, and the longer you run it, the more often this happens.

I bought mine from Northern Tool, and it was a good pump. I used it for a few months and never want to do that again!!!

I'm now looking into running power to my pond and then installing a submersible pump that I will run every night. My plan is to have it run for a certain amount of time, and install automatic sprinkler valves to get all of my garden.

 

[ponytug]

Thanks, as you can see I don't know much about this stuff - and living out in the country for so long I feel dumb that I don't know . Anyway, I probably should have just left out the part about watering off the well because I really just wanted to investigate what it would take to utilize a pond that never dries up. What I really meant to say is that for example, if I fill a bucket at the house it takes half as long to fill it as it does from the hydrant at the well (before it goes into the house). Now maybe that's indicative of some other problem. Our well is about 225' deep and the pump is circa 1980's we believe. We don't know what size pump is down there since we bought this place 6 years ago. If I hook my sprinklers up to the hydrant, I get less coverage on the gardens than I do running thru the house. I don't know why, that's just what it is. And, yes, while we've never had water problems I was concerned about running it low or dry during a drought although I have no idea how unlikely that may be. I have pond that never goes dry though

OK, so I have two gardens and I have two 360 degree rotating rainbird sprinklers set about a third of the way in the middle in each one about 6' high on a t-post. That will currently cover the gardens off of the house with some overlap in the middle of the garden. I've been running one for a while and then switch to the other. I only run one at a time. One garden is 80'X40' and one the other is 60'x30'. I'm just investigating what it would take to irrigate those two spaces from the pond which is approx. 500' away.

We all started at zero, so no worries.

The reason that running the sprinkler from the house is better than the hydrant is the booster pump in the house. Your well pump is (should have been) designed to get water out of the well. The house pump boosts the pressure to a reasonable level (as @plowhog wrote, typically 40-60psi). However, the house pump doesn't have a lot of flow at 40psi, so it can't run two sprinklers well. (It may also be limited by the flow from your well pump.)

So, if you want to irrigate the garden out of the pond, you are going to want a pump that delivers 40-60psi at the garden, at 10-20gpm to run all of your rainbird sprinklers (look up your model on their website to get the total flow). This is when you spend time looking at those pump pressure vs flow charts to find a pump that has a curve at least 10gpm when at 60psi, or what ever your rainbird numbers are. If in doubt, post here, or if you are buying a northern tool pump, talk to their tech service folks who are very helpful, and usually very knowledgeable. This is going to be a more powerful, more expensive pump. An upside would be that it could double as a fire pump if you ever needed it.

It may be much easier to have a pond pump that pumps to a large poly tank (1-5,000 gal) by garden, arriving at the tank at a few psi through a large bore pipe. Then from the tank, have a standard electric house booster pump and pressure tank send it out to the garden. (Or go the route of using low pressure flood/drip irrigation) If that works well, you could always think about longer term solutions like burying pipe and making the pond pump electric. I would think about sizing the tank to be twice what you think your pump would pump on a tank full of gas, so that you could fill the gas tank, start the pump and walk away without needing to manually shut the pump off, or worry about over filling the tank. A smaller tank would be cheaper, but you would need to keep a closer eye on it. In this case, using a tank, the pond pump just needs to have some gpm at say 15psi to overcome your lift and friction in the pipe (don't forget elbows and valves add resistance) to the tank, so you could use a less expensive and less powerful pump.

Personally, if I could get pond water instead of well water for garden, I would go for it every time. Pond water will have more nutrients in it, and it is way, way cheaper to service pond pumps than well pumps. So, if I could take a load off of the well pump, I would.

Does this make sense?

All the best,

Peter

 

[hartmacw]

We all started at zero, so no worries.

The reason that running the sprinkler from the house is better than the hydrant is the booster pump in the house. Your well pump is (should have been) designed to get water out of the well. The house pump boosts the pressure to a reasonable level (as @plowhog wrote, typically 40-60psi). However, the house pump doesn't have a lot of flow at 40psi, so it can't run two sprinklers well. (It may also be limited by the flow from your well pump.)

So, if you want to irrigate the garden out of the pond, you are going to want a pump that delivers 40-60psi at the garden, at 10-20gpm to run all of your rainbird sprinklers (look up your model on their website to get the total flow). This is when you spend time looking at those pump pressure vs flow charts to find a pump that has a curve at least 10gpm when at 60psi, or what ever your rainbird numbers are. If in doubt, post here, or if you are buying a northern tool pump, talk to their tech service folks who are very helpful, and usually very knowledgeable. This is going to be a more powerful, more expensive pump. An upside would be that it could double as a fire pump if you ever needed it.

It may be much easier to have a pond pump that pumps to a large poly tank (1-5,000 gal) by garden, arriving at the tank at a few psi through a large bore pipe. Then from the tank, have a standard electric house booster pump and pressure tank send it out to the garden. (Or go the route of using low pressure flood/drip irrigation) If that works well, you could always think about longer term solutions like burying pipe and making the pond pump electric. I would think about sizing the tank to be twice what you think your pump would pump on a tank full of gas, so that you could fill the gas tank, start the pump and walk away without needing to manually shut the pump off, or worry about over filling the tank. A smaller tank would be cheaper, but you would need to keep a closer eye on it. In this case, using a tank, the pond pump just needs to have some gpm at say 15psi to overcome your lift and friction in the pipe (don't forget elbows and valves add resistance) to the tank, so you could use a less expensive and less powerful pump.

Personally, if I could get pond water instead of well water for garden, I would go for it every time. Pond water will have more nutrients in it, and it is way, way cheaper to service pond pumps than well pumps. So, if I could take a load off of the well pump, I would.

Does this make sense?

All the best,

Peter

Awesome, yes, thanks for your insight. The stink of it is that *usually* our climate is such that I don't need to irrigate much at all, and if I need to do some I'm not concerned about the well in a normal year. So far, this has not been a normal year by far. I got .5" of rain in the entire month of May while the gardens were being planted. We're often TOO wet this time of year. So I have to weigh the cost of such a system with the perceived and expected future need.

I just rigged up a really cheap drip irrigation system for my 60 tomato plants and 12 pepper plants. I used 1/2" PVC with a hose bib connector and drilled a little 1/16" hole to drip at the base of each plant. That's saving a ton of water and just putting it where I need it. It's not helping anything else tho

 

[plowhog]

Would I have to run the same size discharge pipe/hose the whole way (500') and put hose bibs in where I need them or can I neck down to a 3/4" garden hose off of the discharge pipe?

You do not have to use the same size pipe for an entire run. In some circumstances, it is common to use differing pipe sizes, although that is usually more often with elevation changes or other things different from your circumstances.

Water flowing through pipes is subject to friction loss, as the water bumps up along the internal wall of the pipe as it moves along. Using the same pump, if you pump through 50 feet of pipe, the velocity of water coming out the end of the pipe will be much greater than if you pump through 500 feet of pipe.

But, as ponytug also pointed out, it may be disadvantageous to use a gas powered pump moving water directly from the pond all the way onto your garden and out the sprinkler heads. Every time you wanted to water the garden, you would have to go start the pump. Then let the pump run while you water the garden, then go shut it off. If it were me, I would want something requiring less frequent attention. Also, the pump would likely have a lot more capacity than just running a few sprinklers-- so you would be burning gas somewhat inefficiently.

As an alternative, the gas pump could (quickly) fill a holding tank near your garden. Then you would shut the gas pump off. Depending on size, that amount of water might last several days or more without firing the gas pump up again. An electric pump could take the water from the holding tank, pressurize it, and run the sprinklers. That sort of arrangement could also be operated on a traditional irrigation timer. An advantage would be, depending on size of your holding tank, you might not need to run the gas pump for several days, or maybe a week or more.

Finally, if you want to run sprinklers directly from the gas pump in the pond, lots of calculations of pipe size, friction loss, gpm per sprinkler, etc. are needed to ensure success. If the gas pump just fills a holding tank, you need not bother with almost any of that. Because the gas pump will push water to the holding tank-- the only variable being the speed it achieves to fill it.

Hope that helps.

 

[plowhog]

That's saving a ton of water and just putting it where I need it.

That's great! My wife also does drip irrigation for our garden-- putting water only on the plants we want. It reduces unwanted weed growth as well.