#144 - Top 10 You Gotta Know This

The Sprinkler Nerd Show

Welcome back to another episode of the Sprinkler Nerd Show. I'm your host Andy Humphrey. This is episode 144 coming to you on Friday, almost a live Friday. We're gonna get this one aired within the next two hours. So if you're listening to it on Friday, this episode is being recorded at 9.32 a.m. And I'm joined today by

My good friend, Paul Bassett, who joined me last week in my hometown of Traverse City, Michigan for the Iceman Cometh Race. Paul is a survivor. We may talk about that a little bit today, but while he was visiting, we had this idea to record an episode calling it kind of like Irrigators Top 10, and these would be sort of 10 facts that we should all have readily available in our mind at any moment without having to open.

a book. So we're going to kind of talk today about 10 things all irrigators and or landscapers who do irrigation should kind of just know. So Paul, welcome.

Paul Bassett (01:12.718) Oh, Andy, it's always good to hear from you and be with you and come up with these fantastic new topics to do a podcast on. As we were preparing this, I've been in the irrigation business 35 years, so you would think these would all be at the top of mind. As you go through life, sometimes you forget or you don't always use these calculations every day. So it was a very good reminder for me to be able to have these at the top of my fingers and be able to...

the pull them out so probably one thing we should do is text these outer get these the folks and you know have them put it on a screenshot and have it available.

Andy (01:51.774) Yeah, because I mean, really sometimes when you're in the field, you got to make changes to a design, or you want to run a quick calculation for a customer to run an estimate or an ROI. And you can't always just Google something and find it and figure it out or pull out your design book. And so we kind of thought there are some things. We tried to think of 10, of course, to make this episode a 10 list, which was actually kind of hard.

If you're listening to this and you've got other ideas, let us know because this was just a list that we put together kind of top of mind. And when we get started, you'll see that this list is, we're trying to make it sort of memorizable things versus concepts. But I think there are a couple that are concept based, but we really think that these are just sort of the, you know, if we were in school, these would be things you would memorize and there would be, and you would put on a test. You would be asked these questions and you commit them.

to memory, sort of like, you know, how many states are there in the United States? That would be a fact that you'd commit to memory that everyone would know. Just common knowledge. And so maybe that's what we need to call this, sort of like common knowledge facts that irrigators should have top of mind.

Paul Bassett (03:08.834) Or as you say with this particular topic, common knowledge concepts or constants. I even, constants, common knowledge constants in the irrigation industry. And all of these numbers and calculations that we're gonna discuss are all in tests that we've taken in the irrigation industry, whether it's a certified irrigation designer, contractor, and all of these are extracts from any of the textbooks that we've ever read.

Andy (03:15.834) Constance, right. Constance.

Paul Bassett (03:38.422) be a part of.

Andy (03:40.894) Mm hmm. So I think what we should do is, well, first of all, let me congratulate you on finishing the Iceman Cometh race. I'm really impressed because you didn't even hesitate when race registration opened. You signed up and this was six months prior. And this is no joke of a race 30 miles point to point in the woods with 5000 other riders and you just signed up without any hesitation. You flew your bike out to Michigan and.

Boom, you'd finished the race, so congrats, man.

Paul Bassett (04:11.358) Yeah, and it was super fun and I can't wait to do this. Hopefully every year for the rest of my life. I got the bug. It was good to hang out with you and all your friends in Michigan. And I am so excited about next year. I definitely going to do a little bit more training and hopefully my neck won't be as jacked as it has been this last year. So can't wait, dude.

Andy (04:33.09) Yep, anybody who's into biking that happens to be listening to this, check out iceman.com. And if you're interested, register and we will, you know, get a tent for us irrigators and throw a party in the woods in Michigan after the bike race. It'd be a heck of a lot of fun even if we just got two or three other people into biking. You want to come to Michigan and hang out next year with Paul and I in the woods for

Paul Bassett (04:58.422) Can't wait, man.

Andy (05:00.246) Okay, so I think that to kind of set the tone for this, I'm going to say the first one that I want to use to let people kind of understand what we're talking about. So here would be a for instance, you're on a project and you take a static pressure reading and then you see that there's a slope on the hill and it looks to be about 20 feet of elevation from where you took your static pressure reading to the bottom of the hill.

what is it that all irrigators should know about pressure as it relates to elevation that they should commit to memory so that if you take a pressure reading at the top of the hill, you can calculate what your pressure will be at the bottom of the hill.

Paul Bassett (05:47.882) Very good. And yes, this is definitely something, especially if you live, not necessarily in your neck of the woods, Andy, where it's flat and in Michigan, where you are.

Andy (05:56.238) Yeah, but even 10 feet, right? 10 feet to the eye over a distance can look flat. So, you know, many sites have elevation, even if it's only enough where you might need a check valve or something in a sprinkler. But using the what do we want to call this the constant of pressure due to pressure loss, or gain due to gravity, I guess is where I'm going with this would be the constant that everybody should know.

and I would say first and foremost they should commit like a half psi. If they can remember 0.5 psi that's the easiest one but then the actual number is 0.433 psi loss per foot of elevation or gained per foot of elevation.

Paul Bassett (06:46.038) And that's what I've always really put in my mind as I'm doing calculations is half a pound per every foot of elevation. And it makes it easier round. At least you got a little buffer, especially if nowadays, and I know I think you and I really going to talk more about the residential element on this to make it more simplified for people. But, you know, we do a lot of work in commercial and there's a lot that's happening in what we do with green roofs and got to get water to a top of a building. Now that's a hundred.

Andy (06:51.992) Right.

Paul Bassett (07:16.362) stories or whatever it is. So you're like, oh.

Andy (07:18.736) Even if it's six, right? Even if it's 30 feet or 20 feet.

Paul Bassett (07:22.338) I mean, it's a big loss, right? And, you know, we're going to need pumps to get the water pressure unless the building has a booster pump. So a lot of this has to do with making sure you overcome the pressure losses of elevation in your calculations so you don't get stuck.

Andy (07:35.034) Yep. And coming out of a pond, you know, a lot of municipal sites have, you know, secondary sources and a lot of times the pond are at the bottom of a slope. That because generally where you know, the water collects. So whether it's retention basin or a pond, you know, it's good to take that into consideration. What is the elevation of the pump? What is the elevation that it needs to get to? And you can quickly run that calculation by remembering, you know, one half pound of pressure for every foot.

of elevation, either gain or loss. So now that's an easy one. Probably all you guys listening, that's an easy one. But if not, just remember, half a pound of pressure and the actual number is 0.433, but a half pound will always cover you because it's a greater value than the actual value. Okay. So let's go to a second example, number two. Do you have one, Paul?

Paul Bassett (08:07.007) Easy way to do it, Andy.

Paul Bassett (08:30.166) I do. And this comes in a lot of times when you're on a property or you're with a homeowner and they say, well, how much water do I need to apply in my landscape in a given week? What do you do? Oh, let me run the math. Well, first of all, we need to know how big is your property. And one of the calculations that we use is how many square feet are in an acre. And this is something that we

We should all try to commit the memory so you know exactly how much water you need to apply, but you know, 43, 560 is that's how many square feet are in an acre and these are the numbers that you need to be able to have when you calculate how much water is being applied. So you can say, well, I have a half an acre of property. Okay. Well you divide, you know, the 43, 560 and half, and then that's your square footage and then well, how much water do we need a week? We're going to calculate one inch of week.

And then we should be able to determine from there how much water that site needs in a week. And you can tell your customer, here's how much you'll be expecting to pay in water per week in the growing season.

Andy (09:36.418) Now you just covered a whole bunch of shit. Not only the $43,560, but one inch of water, you know, breaking it down to square feet and then telling them how much that's going to cost. That is a whole episode right there. So I'm going to just make a note on that.

Paul Bassett (09:50.19) I did probably overwhelm. Yes, apologize on that.

Andy (09:54.006) Oh good, man, I love it. So 43,560 square feet in one acre. That's what we think is that you should commit to memory. How many square feet in an acre? And.

Paul Bassett (10:06.954) Yeah, and again, what happens too is like a lot of guys and gals are out here when we work in athletic fields, they're going to consume a bunch of water and they're a large area. So this is really where I first started understanding the square footage when we started doing soccer and football and baseball fields because you got such a large area, it's way more than a half an acre. So you got lots of acreage and the client wants to know how much water are we going to be putting down? How much do we need?

So that's where those numbers come in handy more specifically then, than when you're doing residential.

Andy (10:39.878) Okay, I think that then rolls into our third constant, which you kind of started alluding to when you said, you know, how much water is one inch, you know, for gallons. So I think the next thing that should be committed to memory is how many gallons is one acre inch, one inch of water over an acre. How many gallons is that?

Paul Bassett (11:07.498) And one of the things again, for those of us who haven't been into the irrigation show or the conference or taking classes, these are all things that, that like page one and two of our books that go through all these content and then they reiterate it throughout. And, and I think Andy, you did the same with our numbers that a half of a pound per foot will we know that the physical number of an acre inch is 27,154.

Who wants to remember 154 all the time is so hard. Is it 154? Is it 560? So Andy and I make it easy. It's 27,000 gallons. Just like a half a pound. Then that's about right. But it is the actual number is 27,154 and that's how many gallons of water it would take to cover an inch of land over one acre.

Andy (11:38.61) Mm-hmm.

Andy (11:45.834) Mm-hmm. 27,000 gallons.

Andy (12:01.686) Yep, so if your client has a half acre lot and they're just, you know, again using one inch as an estimate, this might be more, might be less, but annualized, let's just say it's an inch over half an acre, then you can take 27,000 gallons, divide it by two, right? You get 13,500 and that would be one inch of water for half an acre. So knowing those constants in your mind would allow you to do some quick math on the fly without opening up any design books.

Paul Bassett (12:31.714) And then why would you apply one inch of water? Where does one inch come from, Andy? Why would we apply an inch? Where does that come from?

Andy (12:39.484) Oh man, you're gonna test me in front of all these people listening?

It's the plant water requirement, right? On the average for, I believe, cool season turf, one inch of water per week. And then again, in the summer, based on the actual evapotranspiration rate, it could be an inch and a half or it could be more. And in the spring, it could be a quarter of an inch or one inch, but when you annualize it, that is the number one inch that is used for, you know, sort of quick math, if you will.

Paul Bassett (13:08.046) Well, you said a calculation or term in your discussion point here of evapotranspiration. What are the four things that create evapotranspiration?

Andy (13:19.954) Cool, well, let's make that our next, you know, not a constant, but the next sort of fact that every irrigator should know is what is ET, evapotranspiration, and then what you said, what are the four variables that make up evapotranspiration for climate, you know, weather variables that make it up. So we have air temperature.

humidity, wind speed, and solar radiation. So those... What's up?

Paul Bassett (13:57.386) Rainfall's not in that, Andy. Rainfall's not in that.

Andy (14:01.894) rainfall would be considered like the counterbalance. So rainfall is used to fill the bucket up, but those four variables are used to calculate the bucket depletion, if you will. So those variables calculate the depletion. Rainfall then fills it back up. So if you had one inch of depletion and you had one inch of rainfall, then you have zero.

The water requirement is balanced out. But evapotranspiration is just water loss. It doesn't have rainfall. Rainfall is just the added value to help estimate the water needed. But it's not a part of the actual evapotranspiration equation.

Paul Bassett (14:50.326) Excellent discussion point, Andy, because sometimes people forget that rainfall is not calculated in ET. It's also sometimes kind of hard to figure out where to get ET data from. It's not like we can go ping a source and we have it all over the country. You have to go find it and it has to be a good reliable source. I think more and more people are starting to...

Andy (15:14.031) Yeah.

Paul Bassett (15:16.822) give access to ET so it's becoming readily available for us.

Andy (15:22.09) It is kind of wild, you know, even when you think about all these smart controllers out there in the world, which when we say smart controller, that means many things to many people. There's really no good quantifiable definition of a smart controller, but it just amazes me that even on the screen, let's just take Hydrawise. Sorry, Hunter, I'm just using this as an example. On the screen of the Hydrawise controller, why doesn't it just show you the ET value?

Like we need to put that in front of people so that they understand why it's doing what it's doing. Show me on the screen what you know yesterday's ET is.

Paul Bassett (15:48.62) I know.

Paul Bassett (15:57.09) Very good suggestion, Hunter.

Andy (15:59.27) So, and Hunter, anyone, right? We should just put it out there. It's as important as how many gallons of water did I use yesterday.

Paul Bassett (16:08.718) Well, I know Andy, we've been kind of talking about some of the little more advanced constants in the irrigation, but let's talk about some that are a little bit easier, which folks really should know as well. And what we're going to do is there's a lot of different pipe types in the world. And we, you and I, when we did this discussion, we wanted to pick something that's a little on the simpler side. So for those who use poly pipe or HDPE.

forgive us, but we just chose schedule 40 PVC is our constant pipe type and it's going to be an average PSI 50. But you know, folks should know how much water does a one inch piece of schedule 40 pipe flow through at a standard pressure? I mean, because when you're out in the field and you're looking at how many heads are on a zone and you know the pipe size and you say, well,

What, why is there 20 gallons a minute flowing on this one inch piece of pipe? And I have absolutely terrible pressure because that pipe should only be running 13 gallons a minute. Now you have 20 and you gotta make an adjustment. You gotta fix it. So, you know, that's something that's really important for all of you listening out there. How much water can we flow through our pipe?

Andy (17:17.072) Right.

Andy (17:27.186) Mm-hmm. And we'll have to save this for another episode where maybe we talk about the concepts versus the facts. So you and I wrote down that we thought it would be important, again, mostly residential speaking to know the maximum flow rate for schedule 41 inch at 13 gallons a minute and the maximum flow rate for three quarter inch schedule 40 at eight gallons a minute. But the most important thing is to know how to find this.

where to look, how to find this, and that would be, you know, understanding a friction loss chart. And friction loss charts are in the back of every manufacturer's catalog, most manufacturers catalogs. And it's important not to exceed a certain velocity. So, you know, this will lead into the next sort of constant that we want to talk about. But the maximum flow rate is determined by the velocity

Paul Bassett (17:56.097) Yes.

Andy (18:25.286) the pipe such that it puts less stress on the fittings and less stress on the systems with water not moving as quickly through the pipe. And so we think that all irrigators should know what is the maximum velocity in feet per second that is used in these friction loss charts. So why don't you tell us what that maximum velocity should be?

Paul Bassett (18:50.838) Well, it's funny you say that because, you know, always handy for me is my book, constant book, that I have to reference all the time because I'm looking up charts. So when you look at, okay, well, we were gonna use one inch PVC, you go down in your chart book, you go, okay, well, what is the flow rate of it? And in all of the books and charts you see, it's five feet per second is the standard in the irrigation industry of how

fast that you're going to move the water through the pipe to ensure that the fittings aren't damaged, the valves aren't damaged, you don't have excessive pressure and water hammer. So five feet per second is what's going to allow us to get our 13 gallons a minute through our schedule 40 PVC.

Andy (19:38.054) right five feet per second. Five feet per second guys five feet per second. What's so fascinating too is when you look at friction loss charts, the friction loss going from like a one inch pipe to an inch and a quarter pipe when you're at that five feet per second is a big deal. You might go from three psi loss per hundred feet to you know or to one psi loss per hundred feet by upsizing

And it's a great example of how faster moving water creates a lot more friction loss. Going back to your point, Paul, if you're running twice the volume of water that you should be through a size pipe, your velocity increases tremendously, which then causes there to be a lot of friction loss. And that's why you put too many heads on a zone. It just doesn't balance out and you get poor performance because of all that friction loss.

Paul Bassett (20:38.474) And I've seen this way too often in the 30 some years that I've been doing this. The client goes, why isn't my sprinklers working properly? What is going on? Do I need a booster pump? No, we need to split the zone. Well, what's that going to cost? Right? You always hear that. Well, I'm sorry, but you know, somebody tried to get away with doing something that they shouldn't have, and now you need to split the zone and out of out. We don't need a pump. We just need to split the zone. And the thing that we're trying to really encourage here is, you know, just do the math.

Andy (20:50.917) Yeah.

Andy (21:02.159) Mm-hmm.

Paul Bassett (21:07.358) It's not that hard. We all have smartphones They can easily go in and plug in some numbers and calculate what you actually need to put on a zone

Andy (21:14.69) Yep. And we know that the smartest irrigators listen to this show. So we know that you guys understand what we're talking about. But what we really want is for you to know, and we think that you do, you know, why? Because we still, there are still installers out there that if you were to ask this question, how many heads can you put on a zone, they're going to say, I put four rotors on the zone. Why? Well, because that's what my boss told me to do. Well, do you know why? Nope, my boss just says four heads on his own.

but they don't know why there's four heads on a zone. And so that's the most critical thing is to understand the concepts so that you can decide if you're gonna put two or if you're gonna put 20, because you know why and then you know how, and then you understand the entire hydraulic, you know, makeup of the system.

Paul Bassett (22:02.862) Well, Andy, what if a customer says, hey, man, my water bill is excessive this past summer because they get billed every quarter. And then they say, can you take a look at our water bill? And they send you the water bill and the water bill, the municipality measures the water in cubic feet instead of gallons, which is a lot of times through most jurisdictions is their water meters measuring cubic feet.

And then you got to do the math to figure out, well, what the heck? How many gallons is that? And this, so there's a few constants that are in there that all of us, irrigators must know when we are analyzing a water bill or we get measurements in cubic feet. And so what do you think those are, Andy?

Andy (22:45.074) Mm-hmm. Yep, well, because I just asked Google, and we know that's what you guys would do and there's absolutely nothing wrong with that. I use Google all the time to run conversions, but knowing that one cubic foot, one cubic foot, one box, right, one box of water is 7.48 gallons. 7.48 gallons, and then I think some meters.

Paul Bassett (22:55.094) zero.

Andy (23:13.118) also record in 100 cubic feet or the bill may come in the form of 100 cubic feet. So then you can just take 7.48 times 100 and you get 748 gallons in 100 cubic feet.

Paul Bassett (23:27.67) And you see, we see that all the time. I mean, you and I run math and looking at utility bills and going, ah, man, these guys with their cubic feet again. But I've seen a lot of municipalities now are making it a little more simplified where they actually will do the conversion for you on the utility bill to show you. Here it is in cubic feet and here it is in gallons so that you don't have to do the math, which is, you know, better for us folks in the U S

Andy (23:47.034) Mm-hmm.

Andy (23:50.866) I know. It makes you wonder why it's like that. It's one thing. I mean, I understand because that's what the meter records it in. So that's what they reported in. But the benefit to the utility is that a lot of consumers don't understand what that means. They don't even know what their water bill is. They don't know how many gallons they're using. So they don't even know if they're using the right amount because those numbers don't mean anything. But you know, it would just be easier if they turned it into what people recognize gallons on every water bill.

Paul Bassett (24:10.219) Right.

Paul Bassett (24:19.786) Well, I think, Andy, from what I recall, that back in the day, way before you and I, that all this water was measured via agriculture. And agriculture used the cubic feet because they had big canals, they had big reservoirs, and the reservoirs were all measured that way. So as we started putting meters on things, that was the simplified form back in the day to be able to do it in cubic feet.

Paul Bassett (24:49.802) measured in gallons. But that is really the reason why it's in cubic feet, not to think that the municipality is trying to pull one over on you or think, you know, we don't know what we're doing. But it was really an old agricultural calculation done back in the day.

Andy (25:02.822) And then to just mechanically on the meters, if it was gallons, you would need a few more number, a few more dials, you know, to because the number is going to be a lot bigger. So you may need a couple more zeros, you know, on the meter reading to actually read that high right of a volume.

Cool, okay, well staying in water, this one is related to irrigation, but it's more of just knowing about water. It might relate to irrigation when it comes to how much a cistern might weigh when it's full of water, but I think it's nice to understand the actual weight of water in terms of how heavy, what does one gallon of water weigh?

Paul Bassett (25:47.954) And not only should you know it here, but when you go pick up a gallon of milk, okay, well, how much does that weigh when you got to carry it, or if you want to carry two gallons of milk, but it also really relates to the pressure that particular amount of water weighs when it creates pressure. So when you're talking an inch or a foot of water, it creates a certain amount of weight that then creates pressure.

Andy (26:14.77) Mm-hmm.

Paul Bassett (26:14.966) So all of us should know that a gallon of water is 8.34 pounds. Or for us easy mathematicians, it's about eight pounds. So it's eight pounds. Yeah.

Andy (26:22.798) eight pounds. Yeah. Yep. Again, it's just nice to know about water moving water moving water in motion. What does water way just good to know some water values.

Paul Bassett (26:33.31) And then, you know, I think this is the one constant that inspired this whole episode really was, you know, we were doing some calculations on, you know, how much does fuel in an airplane weigh? Because you got to do weight balance and your wife said, oh, fuel is 6.1 pounds. I'm like, wow, fuel is less than water. That's because water is 8.3. So, you know, fuel is, ah, this sounds like a great episode, Andy. Let's

Andy (26:46.052) Right.

Andy (26:54.65) Makes sense. Yeah.

Andy (27:00.47) No wonder water no wonder fuel floats on the top of water. I think it does anyway. So all right, well, I think we got our last one here, which is actually more of a concept because these values can change. And so what we thought is that, you know, every irrigator should know the general precipitation rates of drip sprays and rotors.

And again, this has a range, but knowing the precipitation rate of those devices is really important as it relates to scheduling and to understand the reason why you zone things separately, because that's sort of the foundation of zoning things separately outside of the plant material is you want to have the same precipitation rate of all devices on

one zone. So what should we use for general precipitation rates of drip spray rotor?

Paul Bassett (28:09.522) What I've always done when I calculate things is, again, I try to make it simple for me as well. So sprays, I've always used the constant of an inch and a half. And then rotors is about a half an inch. And then drip is somewhere between another half an inch, right? So...

Andy (28:28.962) Yeah, and that's the drip is kind of the craziest thing because I still, it is still very common and popular for contractors to install 0.9 by 12 inch spacing, right? Inline drip, whatever the brand might be, 0.9 by 12. And they don't realize that is an inch an hour, 0.9 by 12. Actually, I think it's even more than that. But then they'll say, yeah, drip, I usually set my drip zones for about 45 minutes because it comes out slowly.

And it's like, well, not at that flow rate in spacing. It doesn't. And that's where Drip, that's where some misnomers are because you could also use a 0.26 by 18 inch spacing. And now you have a pre-sip rate that's more like 0.3 and you should run it a lot longer. Where Drip, you gotta really understand what you're doing because the range is so different. But I think, like you said, generally, it would be more like 0.4 or so, 0.5.

Paul Bassett (29:28.354) I mean, but for this particular discussion, again, we're trying to just make it some simple rules of thumb, sprays and half an inch an hour, I mean, inch and a half an hour, sorry, and then rotors half an inch an hour. And that way you can easily do some simple calculations. Sure, it's going to vary depending on spacing and pressure and whatnot, but, you know, we're just looking for simple concepts here.

Andy (29:47.31) Yeah, yeah. And, you know, Paul and I spent some time thinking of these things and getting more than 10 seem to be pretty difficult. But sometimes you just can't see outside of the things you've already thought of. So if you're listening to this, and we missed some, let us let us know what you commit to memory. And that you think other irrigators and landscapers should know that are those facts that just commit to memory. Because I'm sure we missed lots and lots.

All right, well, I think that covers it, Paul, for these constants. And we got a couple other ideas for a couple future episodes. I really think we should talk a little bit more about giving your customer a water cost analysis. And I would just have to bet that not even one in 100 proposals, new installation proposals, comes with a water cost budget or analysis.

Paul Bassett (30:45.954) Probably not. I mean, you know, the challenge with that is when we buy refrigerators now and washing machines and laundry machines, they all come with what they anticipate that we're going to spend in our energy on these. You know, why can't we do the same here with irrigation? It's not that hard. And it would show your customer you care more about them than the final number at the end of the page that you care that.

Andy (31:01.742) Right. Yep.

Andy (31:10.394) And you know what you're talking about and that you're considering the operational costs of the system. And again, if they're getting a quote, either maintenance quote or new construction quote from three contractors, I bet you your competition isn't doing it. So another great way to stand out is to put together that, you know, cost analysis, operational cost.

Paul Bassett (31:31.35) Great nugget from this podcast right there, everyone.

Andy (31:35.014) Cool, okay, that's the opener for the next episode. Paul, thank you for brain sharing with me today. Love doing that with you, so thank you.

Paul Bassett (31:43.754) can never get enough of doing it as well.

Andy (31:46.926) Right on guys. Thank you for listening. Please share this episode with a friend or share it with your grandmother. And like, subscribe, and we'll catch you on the next episode.

Paul Bassett (32:00.95) Be a Andy. Have a good day. Bye.

Andy (32:01.787) Bye bye.