Do your drippers really put out the advertised GPH flows?

[Mauna Kea Cloudforest]

If you're serious about palms, then you need a drip irrigation that you can trust and that you don't have to rebuild every year.

Matty's recent death of his beccariophoenix no windows left me wondering how accurate the retail home owner drip irrigation equipment really is. The answer is, retail drip irrigation products are junk, there is no attention to flow accuracy, and none of the drippers have the required features to prevent clogging up the lines. I know some people say their irrigation system based on DIG has not yet failed, and perhaps that might be true, that is the one dripper not available in Central California and I didn't bother ordering them to test them. But I can vouch that Raindrip, Orbit and the generic brand sold online by MrDrip are pretty much garbage.

The orbit PC emitters are not PC at all, the flow rate is quite sensitive to the pressure behind the line, and in a single package, the variance in flow rate was quite large, and they work only in a very narrow pressure range. I Raindrip PC emitter test I did showed that after 20 hours of usage, the flow rates deviated across the board, dropping by over 50% on at least 30% of the drippers. Upon returning the drippers to OSH, the manager told me they get 2-3 complaints a week from customers saying the Raindrip clogs up. This is what I am observing as well.

Another major issue for palm growers is the proliferation of fungus harmful to palms. All retail drippers do not provide built-in check valves or anti-syphon. The vacuum created through the force of capillary action of drip is quite intense, and a dripper that remains open when the system is turned off will suck in all sorts of debris which will rot and provide a nice dark and moist environment for harmful fungal pathogens to multiply.

I finally got a hold of Netafilm drip irrigation, and there's no doubt in my mind that this stuff is the holy grail of drip irrigation. I took Perry's advice and went to John Deere in San Jose, they had a bunch of WPC emitters available for much cheaper than the average PC dripper from Home Depot. I also got some of the Tech EZ line to see how it works. I have not tested the Tech EZ line, the biggest issue I have is the need to convert from my 1/4" Orbit manifolds to the 12mm tubing. The pressure behind the manifolds is 60PSI, which is a bit high to connect the hoses directly to my PVC pipe, but apparently this is ok, so I will try it.

The WPC drippers hold a 5' column of water behind so that no matter what the flow and pressure fluctuations are, the dripper will always put out the same precise amount over the period that the system is on. It's got a built in check valve and will shut off once the pressure drops below around 10PSI but it has uniform flow over a wide range of pressures. I can guarantee from personal experience that NONE of the PC drippers available to the retail market perform even close to these curves shown below. I guess the retail drip irrigation product managers must think all homeowners are stupid idiots who just don't care about how their drip system performs.

I tested the WPC drippers yesterday, and they do work perfectly, every single one puts out the same amount of flow regardless of the pressure. I also took some pictures of the brand new PC drippers from Orbit and the flag drippers from Raindrip, which are all complete garbage.

Here is the Orbit 1GPH dripper, you can see it actually doesn't drip, but it sprays out water, who knows at what rate. The pressure behind the dripper is about 30PSI. The orbit stuff is complete garbage, it's junk, I can't believe they sell this stuff and nobody complains. It's worthless merchandise. The flow rates in one package were all over the map, zero quality control. Some sprayed, some dripped at 0.3GPH, some appear to be dripping correctly (about 20% in one package.)

This is the WPC dripper from Netafilm, looks like it's dripping the ideal amount.

The Raindrip flag emitters were even worse, absolutely pathetic. They leaked from the flag, and it didn't take much of a pressure increase to get them to spray, At 20-30PSI they all sprayed.

The bottom line is: buyer beware when it comes to retail drip irrigation suppliers. If you care about your palms, stay away from Home Depot and your local hardware or nursery store, and consider getting a professional grade Netafilm drip irrigation system installed instead. Better yet, do it yourself as none of the shops catering to contractors and professional landscapers are going to turn down your business.

[Sabal Steve]

This is the WPC dripper from Netafilm, looks like it's dripping the ideal amount.

This one seems to actually "drip" where it looks like the other ones you pictured "spray". Or, is this just the cap at the end of the main line?

It seems like an easy way to prevent clogging would be to put a layer of rock, then the dripper, then another layer of rock to cover the line and protect it from the elements?

[Xerarch]

I spent a number of years in the professional landscape industry, Hunter or Rainbird products are pretty good. New drip emitters of these brands are pretty accurate. A good way to test is to take an empty gallon milk jug and place your spaghetti line with an emitter on the end into it, run your system for an hour and see how much of the jug fills up, obviously the amount of time you run the system might depend on the type of emitter you are using. Last time I tried this with a one GPH emitter it over filled the gallon in one hour by just a small amount.

In time though, the inside can wear down, causing more flow than expected, or it can clog up, restricting flow. Be sure to use a filter after the valve to help prevent or at least slow down the clogging. Keep an eye on them periodically and expect that you may have to replace them every so many years to keep the performance that you expect.

[MattyB]

sounds like you're pressure is too high

[KennyRE317]

i didn't any issues with my orbit PC emitters, i have the 1gal and 2gal/hr emitters

[LJG]

If you're serious about palms, then you need a drip irrigation that you can trust and that you don't have to rebuild every year.

Matty's recent death of his beccariophoenix no windows left me wondering how accurate the retail home owner drip irrigation equipment really is. The answer is, retail drip irrigation products are junk, there is no attention to flow accuracy, and none of the drippers have the required features to prevent clogging up the lines. I know some people say their irrigation system based on DIG has not yet failed, and perhaps that might be true, that is the one dripper not available in Central California and I didn't bother ordering them to test them. But I can vouch that Raindrip, Orbit and the generic brand sold online by MrDrip are pretty much garbage.

The orbit PC emitters are not PC at all, the flow rate is quite sensitive to the pressure behind the line, and in a single package, the variance in flow rate was quite large, and they work only in a very narrow pressure range. I Raindrip PC emitter test I did showed that after 20 hours of usage, the flow rates deviated across the board, dropping by over 50% on at least 30% of the drippers. Upon returning the drippers to OSH, the manager told me they get 2-3 complaints a week from customers saying the Raindrip clogs up. This is what I am observing as well.

Another major issue for palm growers is the proliferation of fungus harmful to palms. All retail drippers do not provide built-in check valves or anti-syphon. The vacuum created through the force of capillary action of drip is quite intense, and a dripper that remains open when the system is turned off will suck in all sorts of debris which will rot and provide a nice dark and moist environment for harmful fungal pathogens to multiply.

I finally got a hold of Netafilm drip irrigation, and there's no doubt in my mind that this stuff is the holy grail of drip irrigation. I took Perry's advice and went to John Deere in San Jose, they had a bunch of WPC emitters available for much cheaper than the average PC dripper from Home Depot. I also got some of the Tech EZ line to see how it works. I have not tested the Tech EZ line, the biggest issue I have is the need to convert from my 1/4" Orbit manifolds to the 12mm tubing. The pressure behind the manifolds is 60PSI, which is a bit high to connect the hoses directly to my PVC pipe, but apparently this is ok, so I will try it.

The WPC drippers hold a 5' column of water behind so that no matter what the flow and pressure fluctuations are, the dripper will always put out the same precise amount over the period that the system is on. It's got a built in check valve and will shut off once the pressure drops below around 10PSI but it has uniform flow over a wide range of pressures. I can guarantee from personal experience that NONE of the PC drippers available to the retail market perform even close to these curves shown below. I guess the retail drip irrigation product managers must think all homeowners are stupid idiots who just don't care about how their drip system performs.

I tested the WPC drippers yesterday, and they do work perfectly, every single one puts out the same amount of flow regardless of the pressure. I also took some pictures of the brand new PC drippers from Orbit and the flag drippers from Raindrip, which are all complete garbage.

Here is the Orbit 1GPH dripper, you can see it actually doesn't drip, but it sprays out water, who knows at what rate. The pressure behind the dripper is about 30PSI. The orbit stuff is complete garbage, it's junk, I can't believe they sell this stuff and nobody complains. It's worthless merchandise. The flow rates in one package were all over the map, zero quality control. Some sprayed, some dripped at 0.3GPH, some appear to be dripping correctly (about 20% in one package.)

This is the WPC dripper from Netafilm, looks like it's dripping the ideal amount.

The Raindrip flag emitters were even worse, absolutely pathetic. They leaked from the flag, and it didn't take much of a pressure increase to get them to spray, At 20-30PSI they all sprayed.

The bottom line is: buyer beware when it comes to retail drip irrigation suppliers. If you care about your palms, stay away from Home Depot and your local hardware or nursery store, and consider getting a professional grade Netafilm drip irrigation system installed instead. Better yet, do it yourself as none of the shops catering to contractors and professional landscapers are going to turn down your business.

Axel, a week ago you never heard of Netafim but now you recommend them. Did you install a Netafim system since? Or are you just going off what other people that have used it are saying?

[Mauna Kea Cloudforest]

sounds like you're pressure is too high

The drippers are connected to adjustable flow manifolds, when I dropped the pressure the flow dropped erratically. I don't have that problem with netafim.

[MattyB]

Adjustable flow isn't the same thing as adjustable pressure. I don't think those manifolds should be used for pressure regulation. Sounds like Netafim covers the shortcomings of your system design.

[Mauna Kea Cloudforest]

Adjustable flow isn't the same thing as adjustable pressure. I don't think those manifolds should be used for pressure regulation. Sounds like Netafim covers the shortcomings of your system design.

Eh? The two are proportional, look up Bernoulli's principle. To get higher flow, you need higher pressure, it's that simple. There is no design flaw with the Orbit manifolds, they are actually designed to be screwed on to 60-100 PSI 1/2" NPT outputs. they bring the pressure down supposedly to levels that the average retail dripper can handle, but obviously a lot of the drippers Orbit makes don't seem to work with their manifolds. The pressure on the 1/4" runs off a manifold are typically enough to support about 120 GPH off all eight ports, that's 120 drippers that do 1GPH. You can adjust the flow, i.e. the pressure, same thing, on each of the ports. These manifolds are not pressure compensating, so the downside is that if your pressure drops behind the manifold because you have too much demand on your entire zone, then the flow rate will drop.

The problem with the PC drippers from Orbit is that they're not really PC, and the flag emitters aren't meant to be PC either.

[monkeyranch]

NetaFIM emitters are reliable but the WPC model drippers are not "take-a-part". Clogs are inevitable so I would recommend designs with unscrew-able housings and cleanable diaphragms. The Toro Turbo SC emitters are my current favorite.

[KennyRE317]

Axel, why bother with those manifolds if you already have pvc laid out in your yard, which you must have to put those manifolds on? convert the tube that's connected to the pvc to run 1/2" poly above ground and then run the1/4" distribution tubes with the emitter at the end. also those 1/4" lines can only carry so much water per line

Edited June 14, 2014 by KennyRE317

[Mauna Kea Cloudforest]

Kenny, the reason is that one critter bite into the 1/2 inch poly and the entire system is down. The orbit manifolds make the poly redundant and it's much easier because there is a riser with a 1/4" port always within reach when planting or doing maintenance.

monkeyranch, the Toro emitters sound good, but they don't have the check valve, and that is the primary reason for plugging up. The turbulent flow that these emitters use isn't enough to keep them from clogging. The Netafim are much less likely to get clogged. I do not want to have to clean emitters. That defeats the whole purpose of investing in good emitters.

[Gtlevine]

Axel, it changes nothing to the rest of the system if a line is bitten. I use all 1/2" poly and it works fine. I fix the broken lines while the system is running, no problems.

[Gtlevine]

Here is my setup Axel, easy and accurate.

[Mauna Kea Cloudforest]

Axel, it changes nothing to the rest of the system if a line is bitten. I use all 1/2" poly and it works fine. I fix the broken lines while the system is running, no problems.

Your 1/2" poly can be broken and you still get water into the 1/4" tubes? Really? How?

[David in Berkeley]

Why would anyone buy the cheap OSH/Home Depot drip irrigation emitters and tubing when there are professional landscape irrigation supply stores throughout California? Seems simple minded to buy the low end stuff when professional supplies are readily available. I've been installing drip systems for over 20 years now, and if designed properly, they have been both reliable and fully functional on systems I installed up to 15 years ago. I haven't had problems with clogged emitters, and generally prefer in-line emitter tubing at either 1/2" or 1/4" tubing size for most installations. Local drip irrigation stores such as the Urban Farmer or Irrigation Equipment Co here in Berkeley will help you design a system suited to your conditions at no charge if buying your materials through them. Orbit brand materials are mostly junk in my opinion, I end up replacing them on most retrofits of existing irrigation. If uniform flows are important to your conditions, use of higher end pressure compensating emitters, and layout of distribution lines that acknowledge and factor in topographic differences are the best design strategy. Why try and reinvent the wheel, use the knowledge of experts and professional grade materials. If you know you may have animal concerns with soft drip tubing, it does make more sense to stick with pvc pipe and emitters within enclosures to protect them. Personally, in 20 years of installing drip systems, I've only had problems with poorly trained/bored dogs and pet rabbits chewing through drip tubing. Raccoons, skunks, gophers and moles have mostly left the drip alone. Sun degradation of tubing is a threat, on roof top and balconies where it isn't always possible to protect/hide drip lines from UV light, I find I need to inspect and replace tubing after about 5 years. At the 1/2" tubing size, there is UV resistant brown tubing which holds up longer, but they don't make it in 1/4" or 3/8" tubing sizes. Mulch or shallow bury tubing to get maximum longevity of any tubing, where possible.

[Gtlevine]

Axel, it changes nothing to the rest of the system if a line is bitten. I use all 1/2" poly and it works fine. I fix the broken lines while the system is running, no problems.

Your 1/2" poly can be broken and you still get water into the 1/4" tubes? Really? How?

Yes i do Axel. But your talking the impossible, a complete severe of the line. Even when the Coyotes bite the 1/2" they immediately stop chewing and start drinking when water is flowing, so there is no problem with the rest of the system. The only time ive ever had a complete severe of the line is when an old pipe to pipe fitting completly blew out. But 15 years of this system and thats happened just a few times.

[Mauna Kea Cloudforest]

Why would anyone buy the cheap OSH/Home Depot drip irrigation emitters and tubing when there are professional landscape irrigation supply stores throughout California? Seems simple minded to buy the low end stuff when professional supplies are readily available. I've been installing drip systems for over 20 years now, and if designed properly, they have been both reliable and fully functional on systems I installed up to 15 years ago. I haven't had problems with clogged emitters, and generally prefer in-line emitter tubing at either 1/2" or 1/4" tubing size for most installations. Local drip irrigation stores such as the Urban Farmer or Irrigation Equipment Co here in Berkeley will help you design a system suited to your conditions at no charge if buying your materials through them. Orbit brand materials are mostly junk in my opinion, I end up replacing them on most retrofits of existing irrigation. If uniform flows are important to your conditions, use of higher end pressure compensating emitters, and layout of distribution lines that acknowledge and factor in topographic differences are the best design strategy. Why try and reinvent the wheel, use the knowledge of experts and professional grade materials. If you know you may have animal concerns with soft drip tubing, it does make more sense to stick with pvc pipe and emitters within enclosures to protect them. Personally, in 20 years of installing drip systems, I've only had problems with poorly trained/bored dogs and pet rabbits chewing through drip tubing. Raccoons, skunks, gophers and moles have mostly left the drip alone. Sun degradation of tubing is a threat, on roof top and balconies where it isn't always possible to protect/hide drip lines from UV light, I find I need to inspect and replace tubing after about 5 years. At the 1/2" tubing size, there is UV resistant brown tubing which holds up longer, but they don't make it in 1/4" or 3/8" tubing sizes. Mulch or shallow bury tubing to get maximum longevity of any tubing, where possible.

David, I guess I am a slow learner, took me 10 years of being tormented by my drip irrigation system to finally figure it out. The only part of my old system I am retaining are the Orbit Apollo manifolds in the landscape beds. I suspect I would have run into less problems with the cheap emitters if I had used the 1/2" poly, because the syphon from the manifolds on a hillside is quite strong and is the primary reason my system has failed.

[LJG]

Axel, it changes nothing to the rest of the system if a line is bitten. I use all 1/2" poly and it works fine. I fix the broken lines while the system is running, no problems.

Your 1/2" poly can be broken and you still get water into the 1/4" tubes? Really? How?

Yes i do Axel. But your talking the impossible, a complete severe of the line. Even when the Coyotes bite the 1/2" they immediately stop chewing and start drinking when water is flowing, so there is no problem with the rest of the system. The only time ive ever had a complete severe of the line is when an old pipe to pipe fitting completly blew out. But 15 years of this system and thats happened just a few times.

What do you know Gary. You have only got 15 years of drip experience under your belt and your plants and garden looks terrible.

[Mauna Kea Cloudforest]

Axel, it changes nothing to the rest of the system if a line is bitten. I use all 1/2" poly and it works fine. I fix the broken lines while the system is running, no problems.

Your 1/2" poly can be broken and you still get water into the 1/4" tubes? Really? How?

Yes i do Axel. But your talking the impossible, a complete severe of the line. Even when the Coyotes bite the 1/2" they immediately stop chewing and start drinking when water is flowing, so there is no problem with the rest of the system. The only time ive ever had a complete severe of the line is when an old pipe to pipe fitting completly blew out. But 15 years of this system and thats happened just a few times.

What do you know Gary. You have only got 15 years of drip experience under your belt and your plants and garden looks terrible.

Len, what does that have to do with anything other than snarky sarcasm? No one is saying Gary is inexperienced, and just because someone has done something for 15 years doesn't mean there isn't any room for improvements. I've been doing drip for 15 years and I have very nice palms to show for it too. But I am looking to improve. I've not been happy with how my system works, and I cannot afford to waste a drop given the water rationing. If I didn't have to worry about water, I would care less and keep the status quo I had. A coyote chewing through a 1/2" poly line would equate $50 fine per unit of wasted water. Emitters that don't emit correctly or emit improperly means I can't calculate my output. Replacing clogged drippers is no fun either.

[LJG]

Why do you think everyone is talking to you Axel? I honestly don't care about your drip theories. I was just poking fun at my good friend.

[Mauna Kea Cloudforest]

Why do you think everyone is talking to you Axel? I honestly don't care about your drip theories. I was just poking fun at my good friend.

Sure didn't sound like you were poking Gary one bit with that comment.

[Gtlevine]

Axel, we are all in the same boat with water. But your over thinking this. Coyotes are a pain in the ass, they chew my lines all the time and im always fixing them. Thats why im going to pvc in part of my system. But chewing a 1/2" completely in half is not likely with any animal. Plus, once your down to a drip system the leaks are too small to be much of a waste of water. The only big water waste or problem i have is when the pvc risers get broke, thats a major geiser. My Jlocks are as good as ive found in the market, but like your finding out, no system is perfect. You will pull your hair out thinking there is a perfect system out there.

Thanks Len, i can almost always count on you to give me shit.

[MattyB]

Adjustable flow isn't the same thing as adjustable pressure. I don't think those manifolds should be used for pressure regulation. Sounds like Netafim covers the shortcomings of your system design.

Eh? The two are proportional, look up Bernoulli's principle. To get higher flow, you need higher pressure, it's that simple. There is no design flaw with the Orbit manifolds, they are actually designed to be screwed on to 60-100 PSI 1/2" NPT outputs. they bring the pressure down supposedly to levels that the average retail dripper can handle, but obviously a lot of the drippers Orbit makes don't seem to work with their manifolds. The pressure on the 1/4" runs off a manifold are typically enough to support about 120 GPH off all eight ports.

Axel, you're a nerd, so obviously that means you're smarter than me. But what I've been told by experts, is that you should never use flow rate adjustments to try and adjust your pressure. Pressure regulators are designed to reduce the operating pressure without reducing flow. So it's not a 1 to 1 ratio, from what I understand. Wait, maybe it is a 1 to 1 ratio, but that's bad news because you only want to lower your pressure, not your flow. You can have 100 psi but if you're trying to run it through a 1/4" line you're gonna have problems serving your system.

You say that the orbit manifolds are specified to reduce standard high pressure down to low pressure irrigation levels; this is usually supposed to be 15 psi min. to 25 psi max., in my experience. Is that correct? The only thing I can find regarding that is the Q&A at the bottom of this page where they basically say that you really should be using a low pressure system and not relying on their manifold to do all the work.

http://www.orbitonline.com/products/drip-irrigation/manifolds-and-adapters/manifolds-and-adapters/quad-adjustable-manifold/4-port-adjustable-manifold

I've found that the preset pressure regulators cannot effectively reduce high pressure down to acceptable levels, unless you use at least two of them. My system is set up with an adjustable pressure regulator after the valve, and then I suppliment with preset pressure regulators at the risers, as needed, which is usually only at any risers that occur downslope of the valve/adjustable pressure regulator assembly.

You say the orbit manifolds are rated for about 120 GPH. A single 1/2" line should not exceed 220 GPH, so if you have only 2 Orbit manifolds on a single 1/2" pvc line then you're already exceeding the specified flow rate. Something to keep in mind. If you use 3/4" pvc to serve your risers then you can push up to 540 GPH for that station. The idea is to have as high of a flow as possible, at a low pressure.

[KennyRE317]

Kenny, the reason is that one critter bite into the 1/2 inch poly and the entire system is down. The orbit manifolds make the poly redundant and it's much easier because there is a riser with a 1/4" port always within reach when planting or doing maintenance.

monkeyranch, the Toro emitters sound good, but they don't have the check valve, and that is the primary reason for plugging up. The turbulent flow that these emitters use isn't enough to keep them from clogging. The Netafim are much less likely to get clogged. I do not want to have to clean emitters. That defeats the whole purpose of investing in good emitters.

i ran all my underground PVC as if i was doing traditional sprinklers but knowing i was going to run a few drip and i have filters and pressure reducers on 5 of the 6 zones. within each zone i converted a couple heads in sections so each section zone may have 2-4 different drip line converters and then i just place a cup with a 1/2gal dripper at the end of the line and check it once a week or so after a cycle just to make sure there's water.

[Mauna Kea Cloudforest]

Matty, what you are saying is correct and quite useful.

The orbit manifold system is slightly different from the 1/2" poly lines with pressure regulator. The manifold brings the pressure down from 60PSI to an adjustable pressure between 15 and 25PSI. The 1/4" outputs are not pressure regulated, but they are flow regulated without keeping the pressure constant in the 1/4" lines. I would never run 120 drippers off one line, in fact, I use two to maybe five drippers per port max.

The orbit manifolds are a great way of testing if a dripper is truly pressure regulated. You can reduce the flow coming out of the 1/4" barb, and thus reducing pressure. When I did this with the Orbit PC drippers, I found that the flow varied a great deal over the pressure in the 1/4" line. When the screw was wide open, at 25PSI, the dripper sprayed. With it closed 2/3 of the way, the dripper put out almost nothing. In contrast, the WPC from Netafim stayed super constant, and then would suddenly shut off once the pressure in the 1/4" line was too low.

The 1/2" line with pressure regulator has a distinct advantage over the Orbit manifolds: the pressure is constant no matter what the flow rate (except if you exceed the flow rate for the size pipe as you pointed out) unless you're on a hill, in which case you have to count the vertical drop, adding 0.43 psi per foot elevation drop from where your pressure regulator is. For me, I have a 50 feet drop in places from where the shutoff valve is, so that's almost 25PSI extra in places.

What I have observed is that the retail PC emitters are basically only flow stable over a very small range of pressure, maybe 25PSI +/- 5PSI. The Netafim emitters are stable over a much broader range, namely 10-50PSI. Since the Orbit manifold system is not pressure compensated, the pressure could be all over the map, making it incompatible with retail drippers. This is why the Orbit tech person actually recommended having a pressure regulator behind the manifold. At that point, why bother with a manifold, the 1/2" line is better, which is what Steve was saying.

If I had to do it all over again I would bail on the manifolds and use the 1/2" poly system. But it's easier and cheaper for me to just use Netafim emitters. In those places where I am going to remove the manifolds in favor of the Netafim drip tube, I still don't need to install any pressure regulator because the Netafim drippers are all pressure regulated and can take the full 50-60 PSI in the 1/2" PVC pipe.

With all that said and done, none of the retail drippers are rated for underground. Gary's drippers are safely above ground so that when the system is shut off, no debris flow back into the dripper. Netafim is the only manufacturer that has anti-syphon built into the dripper both stand-alone and in the drip line. That's a significant water saving feature, because an emitter under the mulch is going to deliver water more efficiently than a dripper that has to drip through the mulch. I don't want my mulch to absorb water so it can just evaporate, I want the water to come out underneath the mulch and go straight into the soil.

Finally, Netafim is rated compatible for reclaimed water and even sells a purple colored drip line. I don't know any dripper that can handle lower quality water.

So for the poor folks like us who are getting railroaded into water rationing, Netafim is well worth it.

[KennyRE317]

Here is my setup Axel, easy and accurate.image.jpg

that's pretty much how i have mine setup except with button drippers. i do need to put more mulch over the 1/2" poly line though as the sun is really making it expand

[MattyB]

Netafim sounds like the perfect solution for your setup.

How much are those Netafim button drippers?

[Mauna Kea Cloudforest]

I paid $0.26/dripper at John Deere.

[MattyB]

Thanks