Hi hog,

Please explain in greater detail. Describe the system components in more detail. Give the internet site you were learning from. Thanks. Aloha

hi lehua13
I can not remember which site it was now I have been looking through so many lately,But they have a low flow drip system w/ emitters at 1' foot spacing, and they are irrigating a hill side, the picture showed an air vent at the bottom of the hill on the end of one of the runs of tubing.Then this " tee'd " off and connected the whole system together in one big loop.
So I was wandering if I could do that , I will have 3 runs of drip tubing spaced @ 18" apart per bed .So instead of capping off each end I wanted to connect the 3 lines together. I am watering from a well and the pressure /flow starts off great, but then slows down after say 1/2 -1 hr So I thought this may help my situation, but I do not know I'm just grasping at straws.

Any help would be great ,
Thanks

Hi On the Hog,

I can try to explain the theory of why the loop system doesn't really matter in this case. But first, can you tell me the flow and pressure of your well source and the pressure? If these items change over time let me know what they change to. Is the source of water below or above the hillside beds? What could be a problem is well water clogging up drip system emitters. Filters would be very important but produce pressure losses. Pressure regulators the same. backflow preventers the same. The issue of connecting the lines together or not would be a maintainence question not a pressure or flow aid. Aloha

Lehua13
What drip system would you recommend for a well water application,i will be using a filter though,I was thinking drip pipe but not sure now ,

Hi Hoggy,

I guess you don't want to provide the basic info of flow and pressure from your source to scientifically plan your system, no biggy, so I will provide the trial and error scientific method. Since you have well water to irrigate which may contain particulates, the best way is to irrigate using 1/2" pvc pipe instead of poly and start by drilling 1/16" hole every 8". Why 1/16" diameter holes, because you are going to experiment and probably be slightly enlarging holes as you see what is happening. Soil type doesn't matter because you will be gradually increasing the flow from the holes by witnessing what is going on in the soil. Amount of water doesn't matter because you just run the system long enough to soak the soil enough to fill the voids between the soil particles. Slope doesn't matter because the hole size will be in proportion to your slope for even flow. Put screw-on/off caps at the end of your pvc pipe to flush every so often any build up in the pipe or when you notice holes clogging. Is this some thing you might want to try, there is no math involved? An easy way to determine your flow is to time how long it takes to fill a five gallon bucket. You can get a inexpensive pressure gauge at a hardware or landscaping irrigation store and fit it on to a tee in your mainline. I can help you through this if you like. Of course this is just one of many ways to do this. I believe this is the easiest to maintain and costs the least. If you don't like this system you can change easily to drip. Let's do this project. Aloha

Hi Lethua,
Sound interesting, It's not that I don't want to provide the info , it's just that my well stand pipe usually freezes up all winter,So I will not be able to check this until spring , So if I were to drill holes would this be like a sprinkler hose then, or do you think it would drip ?
Also if my well pressure/flow fluctuates wouldn't it fluctuate in the PVC also withouit some sort of pressure compensated emiters or something ? Or would the pressure regulator do this ? I am willing to give this a try though
Thanks .

Aloha Hog,

It would be nice to categorize this type of system. It is a form of custom drip system with a controlled pattern and size of hole for distribution. It would be more like a rigid form of drip tubing. Yes your pressure cycles would definitely affect your distribution. Each hole saps some pressure and flow from your your mainline. That is why the need to know what pressure and flow you have to work with. It is what systems are designed around. If you have high enough pressure, you can use a pressure regulator to bring the pressure to something within your design range not to blow out a softer poly line. With low pressure you don't need a regulator and it isn't going to matter if you have low and lower pressure. Your system will lack the ability to distribute water during those very low pressure periods. What is the reasons for low pressure and flow from your well? Is it your pump over draws your well yield capacity while it is running? An alternative is to have a pressurized storage tank with enough capacity to irrigate your garden in a day. Do you have an idea of the amount of water it would take to irrigate your garden for one day at full growth of your plants? I believe the rule of thumb is 1/2 gal per plant every three days at 70 degrees. What is the diameter of your well and how deep is it? What type(submersible?) and size(HP) is your pump? I didn't want to go into this depth of information because the gradual increase in holes sizes will take care of most concerns. It sounds like you won't be ready to tackle this problem very soon. The job of drilling the hole takes a while and patience on your part. You could test your system for workability by hooking your pvc pipes up to your house water supply with a pressure regulator (25 psi),but you can't really play with the hole diameters until you are hooked up to your well system. Try to determine your plant type of plant and plant spacing for your garden then your hole patterns can be determined. What do you think? Do some research on plants and especially roots systems of your plants. Growing is all about roots to me. JMHO. Aloha

Go with a looped system (closed loop is a misnomer as a non-closed loop is not a loop at all....think of an unclasped necklace its not a loop, just a length of chain)and use commercially available dripper tubing and/or micro emitters you choose the location of.

No need to be drilling holes in pvc because their is no pressure compensation at each emitter (hole). what does this matter? Pressure compensating emitters ensure that each emitter emits water at the same rate; if you drill holes in pvc, the holes closest to the source/pump will spill a significantly greater amount of water than those elsewhere on the loop and perhaps some will emit none at all.

Though the requests for data others have made are generally valid when designing a system....please consider that you are only watering a couple of relatively small raised beds.

This doesn't need to be a major endeavor, this is perhaps the least complicated type of system you can install.

Definitely install a filter (rated for use with the components you choose), also definitely go with a low flow valve as drip often operates below the threshold of your average irrigation valve (this means the valve may never close), I would put an air relief valve in each bed..

Millions and millions of dollars of R & D have been spent perfecting these systems (like netafim, a world leader in drip technology) why tinker with drilling holes in pipe?

Hi Hog,

I agree with MTG, if you have adequate pressure and flow and drip is the easiest to install especially drip tape. The hydraulic calculations are all done for you. The air relief valve is a very good idea at the start of each bed. But I believe, HOG that your conditions are not ideal and you may get some clogging over time with a well water source. The drilling sizes of the holes is very important to equalize pressure along the lateral lines as your lines go down hill or level, never up hill. The hole sizes will vary smaller close to the source and larger away from it. That is why you start out with very small holes and enlarge them in a trial an error method. This system will put enough water in your plants root zone and no more exactly as drip irrigation does. Gradually drilling the hole diameters by trial and error does this. This method also teaches you about flow and pressure. I can discuss it more as you set up and operate your system. This system is much more labor intensive in drilling the holes but way less expensive than buying retail priced drip items(usually you have to buy more than you need). Check out the costs for the two systems. Google "World Record Tomato Plants" and let me know what system the World Record holder used? Everything depends on the soil and root types and sizes. The delivery system is a wonderful learning experience, the same as gardening. JMHO. Aloha

I'm still a little confused about this system.
The term 'closed system' usually refers to hydr-heating systems. Technically, all irrigation systems are 'closed' systems.

Assuming you have a pump to get the water from your well, just use a pressure reducer after your colonoid/valve, as well as your filters.

Frankly, I think you're going to get more consistent watering with an emmiter system under pressure from the pump.

Use micro-filters, and 'scrubber' valves. (specificallly designed for irrigation water) check your filter and clean often. Use 'larger' emitters and and less time. This will reduce 'clogage'