My well pump at the pressure tank is 45 psi. From one of my exterior facets I
want to run a line to my garden located 300 feet away, to feed a trickle
irrigation system consisting of 20 - 120' trickle tube lines which are each run
off of a 1-1/2" header pipe. Each 120' line has its own turn off valve so that
as many lines as need to be, can either be turned off or turned on at the same
time. Each of the 120' lines water requirements is about .6 gallons per min.
Currently I am trying to feed the entire system with 300 ' of garden hoses all
of which are 1/2" . It seems to me like there is an awfully lot of drop in
pressure at the outlets individual line outlets, and currently I am only able to
feed 1 or 2 of the 120' lines at a time. I would like to have enough water and
pressure to feed more of the lines at a time if possible
1. will this work this way.
2. Would it be better to feed the 1-1/2' header tube located 300 ' away with
a larger diameter piping?
3. Would it be advisable to add a booster pump to the line and / or if so what
kind and how big?
Thank you in advance for your valued advise.
If the 300' hose is level and the garden end is open, 45 psi would give
you 2 gallons per minute. Your flow would be less because the trickle
tubes will need some of that 45 psi.
If you used 3/4" hose and the end were open, you could get 6 gallons per
minute. As the hose won't be open, you'll get less, but you should be
able to feed more tubes than you can now.
There's a pipe sizing chart here if it helps:
It's probably not an issue but creating more pressure costs money
for the extra energy required. Irrigation systems for farm use ran
at 70 psi or so in the old days. Modern ones run in the area of 35 psi.
That supposedly saves about 30% in pumping costs. These things
typically run at 800 gpm or so.
On Monday, May 11, 2015 at 11:15:38 AM UTC-4, Tony Hwang wrote:
I was thinking that too. He needs 12GPM, which isn't unusual, but
there are plenty of wells yielding less than that. It's worth
considering before scoping out the solution. He could also raise
the pressure up from 45 a bit too.
I thought it was six GPM, but it looks like it is Point Six (6/10) GPM.
That would be around 1.8 GPM for the 3 lines. Big difference. That is why
I would think he needs a larger line than the 1/2 inch he has, especially
for over 300 feet.
You are correct. I don't know where I came up with only 3 lines.
It will take a good well to put out 12 gpm for very long at a time. No
wonder he can only run a couple of thoses drip lines. I was looking at some
pipe flow charts and only used the 1.8 gpm that I some how made a mistake
with. I am thinking around here (middle of NC) that a good house well puts
out about 8 GPM. Maybe he has a lot larger than 6 inch well.
Today for curiosity I ran the water out at the facet, and determined that it was
putting out just 6 gallons per min, so i guess it really does nor matter how
much pressure I have, at most i can only use 10 of the lines at a single time,
at the volume required is 0.6 gpm Is that the right way of looking at it ?
BUT I am not able to get that yet, Could it be because i am only feeding the
line with 1/2 " hoses,,,,? If I increased the diameter of the feed line hoases
to 1" , would i then be able to get my full 6 gmp to the field?
On Wednesday, May 13, 2015 at 11:44:05 PM UTC-4, Denny of PA wrote:
Yes. You can't get 10 lbs of crap from a 5 lb bucket.
BUT I am not able to get that yet, Could it be
Whatever flow you have from a 1/2" hose at 300 ft, you're certainly
going to get a lot more from 3/4", and more still from 1". You'd be
closer to 6 GPM, but from physics, you're still not going to get the
full 6 GPM that you have with no resistance at all.
You said you're using it for strawberries and this sounds like
a decent size project. Have you considered using black poly pipe/tubing?
You can probably get a 1" x 300 ft roll of that for less than it's going
to cost for hoses.
Any need for it to be buried? Lawn sprinkler guys could pull that
pipe for you underground in an hour, assuming it's just clear shot,
no trees, etc. IDK what they would charge,
they'd have to bring the pulling tractor over, etc, so it wouldn't
be real cheap, but then it's buried, permanent, etc. Just throwing
it out as an option.
today as a trial I just replaced part of my feed line with an additional 50' of
1-1/2" header pipe , at the 300 ' end and I eliminated 50' of one of the 1/2"
hoses that i was using to feed the head section. , and i was happy to see that i
was now able to get 7 of the 120" trickle line working at a time.
yes trhe larger supply pipe appears to be the answer, I was just using the
hoses because they were available, but now that i know the cure to my problem i
will invest in the poly pipe., and maybe i will be able to get 10 of the lines
working at a time like i would like
thanks again for your help
thank you all for your
simply because I have 20 - 120 ' lines off of my 1-1/2" header line , and if i
run 10 of them at time i water half the garden all at once in about 2 hours.
my total supply is 6 gpm and each 120 ' line takes 0.6 gpm x 10 = 6 gpm , that
is the max that I can possible water at the same time.
THAT ! is the difference. ;-)
OK, thank you all for your valuable input.
Yes for clarification the trickle line tubing uses 0.5 gpm/100' which means in
120' that is about 0.6 gpm in each one.
I imagine that what is reducing my pressure at the outside facet is because at
that point, the facet is located about 50 ' already from the pressure tank which
is located inside the home basement, and to that point that is only serviced by
1/2" copper tubing, so I cannot increase the size of my piping back to the
pressure tank point as someone else had suggested.
I was working on it again today. Someone mentioned that most trickle
irrigation systems are designed to run on 15 psi, that is correct and that is
what I had been using to only get the 1 or 2 lines to be able to be feed at a
single time. But today i decided to remove the restricted PSI attachment in
hope that my flow with the greater pressure would be increase up stream at 300
feet away. When i removed the 15 psi filter, I now found that I was able to
get up top 5 of the 120' lines going at once. I tried opeing a 6th line, and
the volume of water flow was so slow that it then even detracted from the flow
on the other 5 lines.
Tomorrow I am planning to try to obtain some larger supply hoses to see if the
increased water volume be pushed would benefit I am going to buy a roll of 1"
diameter tubing to use as a supply line to replace the 1/2 " to the garden, to
see if this would increase the number of 120' trickle line be utilized at a time
may be increased. . I would be really happy if i could get 10 of them to be
used at once, which means I could water half of the garden at a time for several
hours , and then water the other half.
BTW in case you are interested, what I am watering is 2,000 strawberry plants,
which are planted in 120' rows located 4' apart. Many many thanks to you
all again for your valuable input. I will let you know how the greater size 1"
tubing works out, if I can obtain it tomorrow, or later this week.
On Monday, May 11, 2015 at 11:44:07 PM UTC-4, Denny of PA wrote:
of 1/2" pipe, followed by 300 ft of other pipe, you'll never
support 12 gpm. Once you throttle it back like that, you can put
2" pipe after it and it's not going to make much difference.
Best bet is probably to water it in several sections instead of all at once.
Simply going from 1/2 to 5/8" hose provides a 50% area
increase/reduction in dP; 3/4" would be 36/16--> >2X ((6/8)/(4/8)^2)
That should help quite a lot. Most drip systems are intended to run at
10-15 psi; check your emitter supplier's datasheets for that so if you
run more pressure you'll just have to have a reducer anyway.
As others have noted, make sure you've got the well capacity overall for
12 gpm minimum.
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