Category Archives: Irrigation Design

Aug 14 2012

The heart of your irrigation system: the irrigation valve.


If the controller is the brains of your system the valves are the heart. They control the flow of water through the lines. They are very simple in both principle and design.

This is an example of a typical valve. Details may vary but execution is the same.

Valves have water both above and below the diaphragm. The upper chamber pressure is greater than the lower due to the combination of spring pressure and trapped water. They also have an air space under the solenoid with a bleed hole that is opened when the solenoid plunger is retracted (zone turned on).

Opening this hole lowers the pressure above the diaphragm, the water below forces the diaphragm up and water flows through. Most valves will not open with less than 15 to 20 pounds per square inch of pressure. This is only a concern with extremely low pressure; usually on gravity feed water tanks.

Picking a good valve is simple: stay with a name brand. After that you have few decisions to make. Most people use 1” valves. Simple reasons are they are the most economical, readily available, both new and parts, and provide the flow most residential and small commercial designs need. Even if your design calls for a ¾’ valve use 1”. It doesn’t cost more and if you make changes or expansions in the future you won’t be restricted by the smaller size. A 1” valve will allow up to 25% more flow than a ¾” valve.

The next choice is flow control. Flow control is separate knob or screw on top of the valve and allows you to regulate the water going through the valve. In most cases flow control is not necessary but it does have advantages. If a valve sticks open, one of the more common valve failures, the flow control allows you force the valve closed. If your water pressure is low, either because of supply problems or overlapping valve operations, partially closing the flow control will help the valve close faster and more reliably. It’s cheap insurance to have.

Valves fail in consistent ways. It may not close completely. This could be due to debris, the most common reason, or worn diaphragms. Check out FILTRATION for how to prevent debris. Diaphragms do wear and age, generally resulting in a tear in the diaphragm. Just replace. For a very short video on how to do a repair look at VALVE REPAIR. Valve bodies rarely fail unless suffering freeze damage or shovel hit.

Solenoids will fail over time or the connections to the control box could have become corroded. Check the connections; make sure they are clean. For a simple way to test the solenoid:

 Steps in Creating a Portable Valve Activator.

  1. Take three 9-Volt Batteries
  2. Connect in a series
  3. Connnect one valve wire to the negative pole
  4. Then connect the other wire to the positive pole to activate the valve
  5. If the solenoid is functioning properly, you should hear a “click”

For a more involved but very easy and thorough way to test the solenoid and all wiring look at USING A MULTIMETER.

Aug 7 2012

You filter your coffee, you filter air. Really should filter your irrigation water.


The water going to your irrigation system is probably not as clean as you think. Even if you have municipal water from the best city supply in the country (Austin, TX, Des Moines, IA, Sioux Falls, S.D.) that water has to get to you through old pipes. Many cities still have cast iron pipes as their main lines, some dating back over 100 years. Most homes built before the 1960s have galvanized piping.  Pipes tend to fail from the inside, losing minute rust and other particles into the water. Add in the occasional sand particles that get in the water when pipes or pumps break and are fixed, plus the minor debris caused by cutting and repairing pipes, and there is a whole flotilla of little particles floating in your water.

At this point you are probably thinking “Wait a minute! I drink that stuff! All that garbage goes into me!” Yes, it does. However, your body is better adapted to handling it than your sprinkler system. Besides, didn’t your doctor always tell you iron was good for you? Back to the pipes…

All of these particles go into your irrigation system and accumulate in valves, sprays and emitters. This causes decreased performance and a steady increase in maintenance. It also costs you money in ways you might not expect.  The thing to do is stop it before it happens.

A common problem with irrigation valves is failing to close completely. This leads to water seepage through the spray heads, wasting a great deal of water. Many times the problem is just grit or debris keeping the diaphragm from seating.

What you didn’t know it cost you: paying to fix something that is not broken. When you call a service tech (me) out for a leaking valve chances are good the first thing I will do is replace the valve. Generally I won’t even bother to see if it just needs cleaning. This is not done to save time. It is far quicker and easier to open and clean a valve than it is to cut the pipes and replace the valve.

I do it because people tend to be unhappy paying for service. People get really unhappy when charged for a service call and I look at them and say,  “Nah, I didn’t have to replace anything. I just wiped it off with a rag. It’s fine. Please pay me for one hour labor.” People like seeing things replaced. New is always better, right?

The debris also accumulates in your spray nozzles, causing pattern changes, reduced coverage distance and eventually complete blockage. These are easy to clean: tooth pick, tooth brush and running water. A tech will never clean them. It does take longer to clean these than to replace them.

The best thing to do is avoid these problems all together. Install a T-style filter.

The Vu-Flow screen filters keep out sand and debris. The body is clear so you can instantly see when the filter needs purging or cleaning. To purge, just open the valve on the bottom. The trapped dirty water flows out. If the filter needs washing unscrew the body, remove the screen and clean. You don’t need to dry it off, it’ll get wet anyway.

Various screen sizes are available for different debris sizes.

Sediment
In Water

Use
To Protect

Type To Use:
(Mesh; Micron; Inches)

Coarse Sand; Shell

Sprinkler heads

30 mesh; 533 micron; .021″

Medium
Sand/Grit
Pipe scale;
Well Cuttings

Solenoid Valves
Gear Drive Sprinkler
Domestic Water

60 mesh; 254 micron; .010″
60 mesh; 254 micron; .010″
100 mesh; 152 micron; .006″

Fine Sand/Silt

Poultry drinkers
Household well water
Drip Irrigation
Fogger Sprayer

140 mesh; 104 micron; .004″
140 mesh; 104 micron; .004″
250 mesh; 61 micron; .0024″
250 mesh; 61 micron; .0024″

T-filters are easy to install and maintain. Filtering your water extends the life of your valves and nozzles. Maintenance becomes less frequent, saving time and money.  All in all, a relatively minor investment with pretty good return.

Aug 3 2012

Silly you. You thought ½” tubing measured ½”.


Half inch tubing is literally the backbone of many drip irrigation systems. It is by far the most popular size used.  The only problem is half inch tubing isn’t half inch.  It’s close! Closer than ‘hand grenade’ close. More like ‘electric razor’ close.

 

Piping has specific dimensions. Steel, iron, copper, pvc all have set standards set by ASTM International.  This means that the steel pipe you buy in Maine will fit the fittings you buy in Nebraska and connect to the existing pipe in Alaska.

Plastic tubing? No, no real standards.  The size can vary from manufacturer to manufacturer or even within the same manufacturer.  The term ½” is known as the nominal size, or the industry trade description of the product. As they say in the diet commercials, your results may vary. A lot, actually.

Irrigation 1/2-inch polyethylene tubing is available in different configurations:

1/2-inch – .570″ ID x .670″ OD     1/2-inch – .580″ ID x .700″ OD
1/2-inch – .600″ ID x .700″ OD    1/2-inch – .620″ ID x .710″ OD

Why do you care?  Honestly, the sizes are so close they won’t have much effect on water flow, especially the two biggest. You care because fittings don’t always fit. It’s easy to buy a ½” fitting that won’t fit a ½” tube.

It is important when building a drip system to check the internal diameter of the tubing against the size of the fittings you need. While always buying the same brand of tubing and fittings help it is not a guarantee of fit. The two fittings in the picture are from the same company.  They are not interchangeable. If you put the .520” in a .600 ID tube and clamp down tight enough it should hold. You can’t put the .600” in a .520” tube without deforming the tube.

Before you buy your system take a moment and verify dimensions. Look at the barb fittings  and you see the specs are given for each piece. All you need to do is match them to your tubing.

Fortunately, ½” tubing seems to be the only product with this problem. The ¼”, ¾” and 1” are all consistent in sizing.

Jul 31 2012

In the Time Before Plastic there was Brass.


There was a time when brass nozzles where all you saw in irrigation systems. Why? Well, there were no plastic ones. Hard to imagine pre-plastic, isn’t it?  You had brass, zinc and steel. Brass dominated because of its looks and durability.

The first generation or three of plastic nozzles were rough. Manufacturing technology was not at the level needed to produce a truly efficient, uniform pattern spray nozzle. If you wanted quality and efficiency you went with brass.

Today’s plastic nozzles are very efficient and provide good, uniform coverage. Many of them provide coverage as consistent as brass nozzles. They are also cheaper than brass. Why, then, would people continue to buy brass? There are a number of good reasons.

Normally about now I’d start throwing some numbers and statistics at you to show you why this product is so much better. Not today.  I will note that brass nozzles are available with a 24’ radius. Plastic nozzles tend to stop at 15’.

Our wonderful graphics group had absolutely nothing to do with this graphic.

Why buy brass?

Well, if you are designing a system and can space heads every 24’, as opposed to every 15′,  you save on parts and labor. Parts may be cheap but labor is not. Eliminating heads while maintaining coverage can make a noticeable difference in your costs.

Durability. It’s easy to find brass nozzles 50 years old still in service. Brass is corrosion resistant, withstands hot and cold easily, and resistant to abrasion from debris.  If you see a plastic nozzle 15 or 20 years old you have found an exceptional system.

Abrasion resistance. As clean as it is, your water can still carry sand and other debris. Even with municipal water there can be fine sand and, in some areas, metal particles from inside your old galvanized supply line. When metal pipes break down they tend to do it from the inside out, releasing abrasive metal particles into your water. This fine abrasion can have a cumulative effect on any nozzle. Plastic, being softer than brass, will show wear far earlier. The particles will also adhere to the side more readily, causing a build-up that has to be cleaned more often than brass.

Hot and cold. REAL hot and REAL cold. Extreme temperatures: brass has survived them just fine for centuries. Get cold enough and plastic can get brittle. Fine if no one bothers it until it warms up again, not so fine if someone steps on it.

And the main reason people still buy brass nozzles: they look good. Architects don’t recommend brass for door handles, desk trim, railings, faucets, lighting, fountains and more because it’s the latest thing. They use brass because it looks good and stays looking good for a long time. Brass gives everything a classic, finished look.

You work hard to make your place attractive. Very few parts of your irrigation system show to the public. Shouldn’t those parts reflect the pride and work you have in the rest of your home and last just as long?

Jul 24 2012

SPF = Some People Fry SPM = Some People Melt


Couple of safety issues to go over today. We want to keep our customers healthy and buying stuff.

Some people fry.

No sunburn. Sunburn = bad. Too much sunburn = cancer = really bad.

I’m not going to pretend to be an expert on sunscreen lotions. I do, however, know how to get a bad sunburn, if that helps. In researching this post I came across the expected advice and two more things  I didn’t know. So use sunscreen, stay in shade, cover your skin, etc.

First thing I didn’t know: SPF probably doesn’t mean exactly what you think and it’s not really mathematical. The really high SPF ratings don’t do what you would expect. Because he sums it up so eloquently I’ll quote Dr. James Spencer as reported on the very useful WebMD site.

“SPF is not a consumer-friendly number,” says Florida dermatologist and American Academy of Dermatology (AAD) spokesman James M. Spencer, MD. “It is logical for someone to think that an SPF of 30 is twice as good as an SPF of 15, and so on, but that is not how it works.”

According to Spencer, an SPF 15 product blocks about 94% of UVB rays, an SPF 30 product blocks 97% of UVB rays, and an SPF 45 product blocks about 98% of rays.”

And now, the best technical summation I have ever read.

“After that, it just gets silly,” he says. (webmd.com: sunscreens)

The other thing I learned is that, while SPF 45 is not three times as good at SPF 15, many doctors still recommend it and higher but not because of the minor increase in efficiency. It seems most people do not apply sunscreen properly, usually applying far too thin a layer. By recommending higher SPF they hope to compensate for the fact we don’t read instructions.

Oh, and wear a hat.

Some people melt.

If you don’t count holes, snakes, saws, shovels, picks, trenchers, mud, sun, mosquitoes and PVC cutters then there are very few hazards in irrigation work.  So let’s forget those and look at primer and cement.

Working with PVC primer and cement is easy and quick. With any minor precautions at all it’s pretty safe. Even with no precautions it is hard to hurt yourself unless you try. Unfortunately, people seem to try all the time.

You should wear gloves. The primer not only stinks but it will help you find every cut and scrape on your hand and set them on fire. Do you really want that stuff going in an open wound? It also tends to dry out your skin and you lose that ‘satiny smooth’ touch you’ve worked so hard for.   Then you get the great fun of telling everyone why your hand is purple. The cement can take a day or two to come off and you look like you have Rigelian Fever.

The cement is really a solvent. It loves to melt plastic. Get some on your new eyeglasses and you’ll need another pair. Get some on your contacts? Not only will your eye scream in pain but your contact is shot.

Keep cement and primer out of your eyes or your kids will hear those words they aren’t supposed to say.

Now the serious part. Primer stinks. Badly. Primer vapors are bad for you. People will pour it on rags, hold it up to their nose and breathe deeply for a dumb and dangerous high. Dangerous and you end up with a purple nose telling everyone you are less than smart. Make sure you use primer in a well-ventilated area.

Most situations are low risk: the outdoor repair, the quick under sink fix, etc. The danger lies in lots of exposure in confined areas. You will stop smelling it. Your brain will think the nose is lying to it cuz’ nothing can smell that bad that long. The brain stops registering the odor. You can stand there breathing in all the vapors without the built in alarm system your body started with. This is known as ‘not good.’

In 20+ years of working with primer and cement I’ve never known anyone to be harmed during routine use. I have seen people working in small closed rooms get dizzy from the fumes. It’s neither fun nor funny.

Have lots of ventilation when gluing pipe. Outdoors is best.

The bright spot is if you are at risk of sunburn doing repairs it’s not likely you are in a small closed room.  Keep your hat on, use sunscreen.

Jul 20 2012

How we picked our team. Irrigation supplies, major league


Ever wonder why a company picks certain products to carry?  Sometimes it is obvious: if you are going to sell groceries you need to sell Kraft products. Sometimes it is not, like the Tabasco flavored tequila now on the market. Don’t try that one. Seriously.

Choosing the product lines for Sprinkler Warehouse involved both the obvious and the lesser known. The major requirement of each brand was that it was reliable, did what it said it would do and would show our pride in our company.

The obvious. You cannot discuss irrigation without involving Hunter and Rain Bird. Both of these companies are dedicated to irrigation and produce a full line of products. It would be extremely difficult to think of an irrigation requirement that they cannot fulfill.

There are a few others.

The one you’ve heard of but didn’t think about for irrigation.

The Toro Company. Ever wonder why it’s named “Toro”? I did. Seems it was started in 1916 to build tractors for Bull Tractors. Fits right in there, doesn’t it?  Toro is most famous for its commercial and residential lawn and tractor equipment, snow blowers and utility vehicles.  Not as well known is the fact Toro has been in the irrigation business since 1962. They produce a full complement of irrigation supplies and have one of the most innovative controllers on the market, the battery operated and waterproof DDCWP. They also produce the highly efficient Precision Series spray nozzle.

Some you may not have heard of but need to.

The K-Rain Corporation.  It’s not often you find a company started by a rocket scientist. This one is. It was founded 1974 by Carl Kah, a former manager of the U.S. Air Force’s reusable rocket engine program. According to Carl, “Thespace program set an example for all of us in business to follow. There is always something that needs to be improved.”  K-Rain keeps improving, having over 90 patents so far, including one for the Indexing valve, a Kah invention that reduces the need for five valves down to one. Their continuing quest for improvement enables them to bring quality products to market with prices noticeably lower than many of their competitors.

The DIG Corporation. DIG was founded in 1981 to do one thing and one thing only: provide efficient, cost effective low volume irrigation systems. “Low volume” is commonly known as drip or micro irrigation. That’s all they do and they are very good at it. They have anything you can think of for a drip system, whether it’s in your garden, your flower pots, under turf or in plant nurseries. They drip, spray, fog, mist and stream. They also provide the LEIT controllers. Powered by ambient light, LEIT controllers are much more sensitive than solar power, giving you more options for controller locations.

Cyber Rain Inc.  No other irrigation controller out there is as versatile, flexible, high-tech and just flat cool as the Cyber Rain Cloud controller. Need shade, order up a cloud, no problem! (sorry, couldn’t resist.) The Cyber-Rain Cloud controller does everything you can ask for and you control it from anywhere. Whip out your Android, iPhone or Blackberry phone, check your system performance, make changes and, instead of Zone 1 or Zone 4 you see a picture of the area. Why remember zone numbers when you can see what it covers? It checks the weather and automatically adjusts your irrigation schedule to match and, since Cyber-Rain uses the internet, weather updates are always free! Now folks, that’s pretty hard to beat.

Every member of our team was drafted after careful consideration. We’re glad to have them and look forward to the upcoming series/bowl.

Jul 18 2012

Don’t listen to your sprinkler repair man. Better yet, don’t ask.


I’ll start by telling you that’s what I do. I repair sprinkler systems. This does cause a problem, as I’m telling you not to listen to me. Luckily, that’s handled by quantum metaphysics and we can skip ahead.

We are frequently asked: “What’s the best —?” Truth is, we usually don’t know. What we do know is what works for us. We have two basic requirements: we want to make a profit on the repair and we want the product to be good enough that we are not called back for warranty service. This defines our ‘best’ product.

We lose money on warranty repairs. This is bad.

We are also a conservative bunch. We don’t want to be the first one to try the new product and see if it lasts. We go with what we know.  We use the same rotors, the same controllers, the same pop-ups time and again.  I’ll go over a few of those and what might be better.

Pop-ups and nozzles

The Rain Bird 1800 series is one of the most popular popups out there, if not the most popular. It’s my default purchase. Why? Because in the years I was training my supervisors told me to go with the 1800s. Who am I to argue with the boss? Therefore it’s what I know and what I recommend.

What about the Hunter Pro Spray, Toro 570Z, and K-Rain 7800? All good, all in the same price range. The one you’ve never heard of, the K-Rain, might have the best seal in the bunch. Looks that way in drawings and specs. However, I install 1800s and don’t want to experiment.  See the problem here? I’m passing on a potentially better popup available at the same price just because I don’t want to try it and risk a warranty call.

How about nozzles? Rain Bird, Hunter and K-Rain are all extremely popular, pretty much same precipitation rate, all in the same price range. Which is best? Might be the Toro Precision nozzles. In a 12’ full circle spray they use about 1.3 gallon per minute less. Other sizes have similar savings.  Minimizes run off, helps with low gpm systems, and has an efficient pattern.  Why don’t I use and recommend them? They cost twice as much, if not more, than the others. People don’t want to pay for something they really can’t see and one nozzle spraying water looks like any other.

A quick note about something you’ve never heard of: K-Rain. K-Rain makes good products, has 90+ patents in the industry, is very competitively priced and apparently has one of the worst marketing programs around. Have you ever heard of it? People who don’t have irrigation systems know of Rain Bird, Hunter and Toro. There are many pros who don’t know about K-Rain. It’s hard for someone to recommend something they’ve never heard of.

Rotors

The most popular rotor out there is the Hunter PGP. Sells by the tens of thousands. Is it the best? Don’t know.  I sure put in a bunch of them. To be honest I like the Rain Bird 5000 “Rain Curtain” spray coverage better. The Toro T5 and the K-Rain 11000 series are in the same price range but you get a 5” pop-up instead of a 4”.  An extra inch for nuthin’. But people know Hunter and it works so I stay with it.

Controllers

I like and install Hunter. Good and reliable. That’s not the main reason I install it. Look at the face of Hunter controllers. They all look the same. I don’t have to worry about going to service a system and having to remember different brands or carry manuals with me. And, of course, I tend to recommend Hunter for the same reason.

Now look at  K-Rain series. Their controllers  are usually lower than both Rain Bird and Hunter, they also have a standard front and they are reliable. I could save you money by installing them if I were a bit more adventurous. Unfortunately, I’m a coward when it comes to money and warranties.

The point to all this is that your repairman will give you a safe answer. He works in the field all day, knows what works for him and  makes his life easier. The product might or might not be the best but it will be safe for him to recommend and it will work.

There are a lot of products out there that don’t get the exposure they should. Check our site for ideas. At Sprinkler Warehouse we try to give you all the details along with links to different manuals. A lot of information there to help you make a better choice and far more variety than many repair people have ever seen.

Jul 13 2012

It’s the little rotors’ turn to turn, turn, turn…hmmm…I should put that to music.


Like the Little Engine that Could, some rotors just refuse to accept limitations. There is a whole bunch of over-achiever rotors available for smaller systems or smaller areas just eager to show you what they can do. Retro-fitting an old system? Need to cover a smaller area? Only have a ½” supply line? Listen! You can hear them yelling “Pick me! Pick me!”

Take a look at the K-Rain MiniPro, the  Hunter PGJ, the Toro Mini-8  and the Rain Bird 3500. Designed for smaller areas and retrofits these rotors fit areas too small for standard rotors but too large for standard spray heads. Coverage on these range from a low of 15’ to a high of 37’. Since most spray nozzles stop at 15’ and most rotors start at 25’+/- this fits right in.

Since they use a ½” connection you don’t need to run new pipe to get the same type coverage as their bigger siblings and you can match their precipitation rate. Have an older system that no longer provides the head to head coverage it should? Simply use these to regain coverage and possibly eliminate a head or two. For example, if your spray heads are 15’ apart you can replace each head with one of these set for 15’ or you could replace every other head with one of these set for 30’, eliminating the middle head.

For mid-range coverage they do everything the bigger rotors do and do it just as well.  And they are far more enthusiastic.

Once again I want to say that our talented graphics department had nothing to do with these graphics. Don’t want to embarrass them.

Jul 11 2012

Specialty nozzles to nuzzle.


Ok. Not nuzzle. Couldn’t think of a good title. Some people say I never do.

I’ll get down to business. Most people know about the average, used everywhere nozzles. If you don’t then check out sprinkler nozzles. These generally do the job and are all most people will ever need.

There are a number of specialty spray nozzles available for increased water efficiency, problem areas or special applications.  Normally I avoid naming particular brands and products, preferring to give general information. This is the exception.

The first is the Toro Precision Series spray nozzle. While this is not technically a specialty nozzle it has some advantages over competing spray nozzles. The Precision Series has something they call H²0 technology which puts an oscillation on the spray . I’m sure the H20 name has nothing to do with the scientific name for water. Pure coincidence.  Anyway, quoting Toro, “Using patented H²0 chip technology – and no moving parts – each Precision Series Spray nozzles creates one or more high frequency oscillating streams to achieve the desired arc and radius with 1/3 less water usage.”  Yup. Sounds cool. But looks even better.

Ok. Pretty pictures and lots of marketing fluff don’t mean much without the facts. Comparing the Toro Precision nozzle to two major competitors:

Radius/ Feet Pattern GPM @ 30 psi Difference GPM
Toro 15 Full circle 2.31 —–
Brand A 15 Full circle 3.72 +1.41
Brand Z 15 Full circle 3.70 +1.39
Toro 15 Half circle 1.16 —–
Brand A 15 Half circle 1.86 +.70
Brand Z 15 Half circle 1.85 +.69

You might ask “If these are so good, why aren’t more people using them?”  Good question. Thanks.  The only downside to these nozzles appears to be the price. The Toro Precision sells for roughly 2.5 times the cost of standard nozzles. That can make noticeable difference in installation costs for an entire system. However if you are in a retrofit or repair situation and need to have better control over your precipitation, fix a zone that has been expanded beyond capacity, or control run off on slopes they offer you some valuable options.

Let’s talk about Rain Bird Rotary Nozzles.  These cover a radius of 13 to 24 feet. Their big advantage is the ability to match these to the Rain Bird 5000 rotor series and get the same precipitation rate.  Let’s say you have a large area that will be covered by rotors and a small area next to it, say 20’ x 20’. Normally the smaller area would require its own zone using spray heads on pop ups. With Rain Bird Rotary nozzles you can now cover the area with one zone and get the same precipitation rate. Use the 5000 rotors for the large area, the rotary nozzles for the small one. You’ve eliminated one valve, the wiring and one zone requirement on the controller.

Because of their low precipitation rate they are very good for watering slopes. The slower precipitation rate gives the soil more time to absorb the water, minimizing run off.

Next is the Rain Bird U-Series.  In a perfect system you have head to head coverage. Most sprays do well on the far  coverage but lack real coverage in the first couple of feet out from the nozzle. Head to head coverage means that the area missed by head A is now covered by head B. In many cases, due to poor design, changing landscape or deteriorating systems, this no longer occurs and you get dry areas around the head. The U-series has a second nozzle for greatly improved close in coverage. While not as good as head to head coverage it sure comes close.

This is beginning to sound like a Rain Bird advertisement. Not intentional, it’s just the way the nozzle sprays…

Now we have the lovely and talented Rain Bird SQ series nozzles. The SQ stands for square pattern. These put out a true square or rectangular pattern with edge to edge coverage. Most square pattern nozzles aren’t. On that I can speak from experience.

The SQ offers two settings so one nozzle throws 2.5′ or 4′, changeable with a simple twist of the top ring. It has a pressure compensator built in and fits standard pop ups and risers. It is also pretty low flow, using only .46 gallons per minute at its largest setting. Having a square pattern helps eliminate the waste that occurs when you try to match half and quarter circles to cover a narrow rectangular pattern.

And remember, if you are getting enough rain you need to muzzle your nozzles. Get a sensor.

Jul 9 2012

Why didn’t the soil sensor want to party with the rain and rain/freeze sensors? BECAUSE THEY WERE ALL WET! Hahahaha…get it? All wet? Huh? Never mind….


I could have said “because he was well grounded and they were stuck up!” Would that have been any better? No?  Ok. I’ll stop.

Today’s controllers can do a number of things: multiple programs and start times, rain delays, soak cycles and more. They do it routinely, day in and day out, like nice little robots. But what happens if the conditions change? What if you don’t need more water? Tropical storm comes through and drops six inches of rain and your system is still running? What if your grandma is showing her favorite ice hockey moves on your frozen driveway? Need more ice?

Sensors are the answer. A sensor will turn your system off when there has been enough rain, or a freeze hits or if your soil just doesn’t need the water. This saves money on your water bill and, in the case of freezing, can prevent that lawsuit from when Grandma misses the goal and the puck flies across the ice into your neighbor’s window.

The simplest is the rain sensor. Easy to set, almost maintenance free. The rain sensor connects to your controller, either in a direct wire or wireless connection, and stops irrigation after a certain amount of rain has fallen. You mount it in an open area, such as the eaves of your house. You determine the amount of rain that causes the shut down, usually from 1/8” to 1”. To set the sensor you simply turn the top to the proper setting. That’s it. Rain comes down, sensor gets wet. When it gets wet enough it stops irrigation. Some rain sensors suspend irrigation immediately during rain events without need for rainfall accumulation. It rains, they stop.

Rain/freeze sensor. A rain/freeze sensor handles rain just like the standard rain sensor, either on accumulation or immediately upon rainfall. They add the advantage of shutting irrigation down before the water sprays and icicles and ice patches form on your yard and drive. The most common sensors stop activity when the temperature reaches about 37 degrees. Some models let you choose the shut off temperature, ranging from 35 to 45 degrees. The irrigation remains off until the temperature warms to above the freeze cut off settings. The rain/freeze sensor looks pretty much like a standard rain sensor.

The moisture sensor is a different kind of creature. The moisture sensor is buried in the ground, not up high. It doesn’t care if it rains or freezes. All it cares about is keeping the correct amount of water in the soil. If the soil has sufficient moisture it interrupts the irrigation cycle. Too much water in the soil can be just as harmful as too little. The moisture sensor aims for the proper range of moisture.  When the soil gets too dry it turns the cycle back on. With a direct read on soil moisture you don’t worry about wasting water through unnecessary irrigation.

With the proper sensors you can save water and money by watering only when needed. You also decrease liability by preventing icicles  and hazardous ice patches on the drive and walk.  The only downside is that Grandma might be upset you took her ice rink away.