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Garden irrigation planning. Need help picking appropriate water pump and float switch

bbhaag

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Jul 2, 2011
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So I'm planning to irrigate our garden this year using a combination of municipal water source and natural water collection via a 55 gallon rain barrel and using a 750 gallon holding tank. So right now I'm planning/purchasing the parts and pieces required to get water from the rain barrel to the holding tank. So my plan is to place a pump and float switch inside the rain barrel and use a 3/4" garden hose to move the water around 125-150 feet away to the holding tank. Were I need help is picking out the appropriate float switch and pump.

I've been looking around at Grainger for a vertical float switch but I don't think any of them will work. I need a float switch with around 30 inches of rod/float length because I want to install it inside the rain barrel. So the pump stays on until the barrel is empty then turns off until the barrel gets full. If this doesn't make sense let me know and I will try to clarify. I know my terminology isn't exactly pro.

So the second question is regarding the pump. What size pump will I need to do this task? I'm thinking a 1/4 hp pump pushing around 5gpm should keep up even during heavy rain fall. Does that sound about right? I've used a couple of online calculators but ya know how those are....I will have and overflow coming off the barrel leading away from the foundation just in case the pump can't keep up.

Anyway this getting a little long so here is a pic to kind of show what I'm trying to do. Let me know if you have any suggestions especially on the float switch for the pump.

irrigation.png
 

bbhaag

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Jul 2, 2011
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I just had an idea for the pump. Would something like a typical 1/2hp sump pump work inside the rain barrel? That way I could skip the vertical float switch. I'd have to rig some pvc fittings off the output to get it down to 3/4" garden hose but I can do that pretty easy with stuff from Menards.
 

deadlyapp

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Apr 25, 2004
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What you need to know is the head or pressure of the pump. You can calculate the pressure or head loss of the hose length based on the size of the hose and flowrate, which you can use to select the pump.

No reason why you can't use a sump pump vs a normal horizontal pump, same limitations, etc. Sump pump will usually have a self contained low level switch to turn off. I suspect there are some sensors you could

No reason why you couldn't install the float switch lower in the barrel, so that as the barrel gets close to empty, it shuts off. Your barrel would operate lower than normally expected if you take this route.
 
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BoomerD

No Lifer
Feb 26, 2006
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While this isn't exactly what you're doing...the principles are the same:


 
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bbhaag

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Thanks guys appreciate the input. All the parts and pieces are starting to trickle in and I'm hoping once I get it all laid out in front of me it will help me visualize it. I've got a big enough space at work were I can lay it all out to the appropriate lengths and see how well it works before I put it into practice at home.
I think for right now I'm gonna try the sump pump route to help keep it simple but if that doesn't work out I'll have a few more questions. haha
 

Sukhoi

Elite Member
Dec 5, 1999
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You might want to consider polyethylene tubing for the long run instead of a garden hose. Way better with the UV exposure than most hose, and quite durable. I'd get at least 3/4" tubing to reduce your friction losses over that distance. Have ordered a bunch of stuff at dripdepot.com over time and highly recommend them.

https://www.dripdepot.com/item/polyethylene-tubing-size-three-quarter-inch-820-inch-inside-diameter-by-940-inch-od-length-250-feet looks like $67 for 250 ft. Let it cook in the sun for a couple hours then unroll it in a straight line. PE tubing does have a fair amount of expansion/contraction from temperature swings, so leave enough slack.
 
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herm0016

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Feb 26, 2005
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ok, I was waiting to reply to this till I got a little time.

looks like you have plenty of advice on the transfer pump. I would run a submersible for your transfer pump so you don't have to deal with priming the pump. you just want to have a float switch so that it will not run when its low on water.

I really like the bhyve controller from orbit. I have one on my garden system that is 12 x 1in sprinkler valves and the controller all built into a plastic deck box. all the valves have threaded pipe going to the front of the box and i can screw on a garden hose or poly pipe depending on the fitting. its fed by a 3/4 pex line about 100 feet from the back of our house, and its 3/4 or 1 in pex all the way to the meter from there, plus a 1 in backflow preventer at the house. we will also use this controler for the yard system we will get professionally installed this year. I also ran a 20 amp 110 volt circuit to the greenhouse, garden, chicken coop and shed that has been great.
I would look at something like this to feed the watering system:
That controller also has a spot to run a pump relay and you could even set up something in the rain sensor slot to prevent the pump from running when the tank is low. You probably want something with a pressure switch for the sprinkler system, as the drip lines are going to want about 25 psi to get the rated output. my city pressure is about 80 psi, so I had to run a prv to get down to about 40 psi before the valves and inline prvs on all the drip runs after my valves.

This type of pump will adjust with demand and keep the pressure roughly constant to keep your system consistent in its amount of water delivered. you can also set the pressure which will make the valves and drip lines much happier. i'll have to find some pictures. for my raised beds, i use sectoins of pvc pipe a max of 10 feet long with 3/32 holes drilled about every 10 inches. this works great for most crops. on my in ground beds i run drip to things like squash, beans, tomato's, berries, etc. for things like onions and lettuce, i run a few feet of the soaker drip line around the area.
 
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bbhaag

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Thanks guys appreciate all the input. I've got most of what I need already including 1000' of 1/2" poly tubing, 15psi pressure regulator, hundreds of 1.5' stake style drippers, a 120 micron mesh filter, valves, end caps, oh god the list goes on and on.....haha I think for now I'm just going to turn the individual zones off and on manually but it's nice to know you've had success hooking up a controller to your system. Honestly that is very cool.

I still need to head to Menards and piece together the manifold for it but that shouldn't take long. I'm using a similar setup to what I've used in my greenhouse to irrigate our hanging baskets and I know Menards has most of what I need. What they don't have I can swipe from stash at work.:) That's just between us though....haha

I put together a 10' section to see if my system would work if I remember I'll throw up a short vid so you guys can check it out and give some more recommendations if you have any. I guess that's it for now....thanks again.
 

bbhaag

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Jul 2, 2011
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So I had a little time after work today to shoot a short demo of how some of the irrigation will work. It's only three minutes long but let me know if anyone has some other suggestions.

 

Sukhoi

Elite Member
Dec 5, 1999
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Seems like you have it down pretty well. If you need to adjust the watering frequency much between the zones I really recommend taking the time to put in electronic valves. It's easy to glue together a PVC manifold for them.
 

bbhaag

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Jul 2, 2011
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It has been awhile but I wanted to post a quick update. With the warmer temps I've had a chance to get the rain barrel and holding tank in place and functioning. We've had a few showers over the past day or so and I'm happy to report that the 1/2hp sump pump inside the rain barrel was able to keep up. No heavy down pours yet though.

I also started piecing the manifold together tonight after work. I've expanded it from 10 zones to 14 which should give us a little bit more flexibility. Each zone will be on 3 foot spacing so that should give us around 24 feet total. Anyway enough talk how about a couple of pics.


Sorry for the night pic but It was getting late and I was trying to finish it up. Yes I know the lid isn't screwed on. The clay colored hose runs 75 feet over to the holding tank. The fittings and hose coming out the front are the overflow protection in case the sump pump can't keep up or fails. It runs six foot away from the foundation and I went with hose so I can move it to mow.
IMG_20210407_204254442.jpg


This is what I got done on piecing the manifold together. Like I mentioned above each one will be three feet apart. I know some of you guys said go electric but for now each zone will just be manual to help keep is simple. I still have to cut the 3/4" pvc pipe into three foot sections and cement everything together but that is for another day.
IMG_20210407_204206594.jpg


So of course right after I made this post it started raining pretty good. So I thought I would make a short vid showing how it works. Nothing pro or anything like that but it gets the point across.
 
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herm0016

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Feb 26, 2005
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is it time for a garden tour thread?
we have plants under the row covers.

around here, and in the north the saying goes "if you are not afraid of a frost, you waited too long to plant" because the season is so damn short. our p80 last frost is like may 10 or something!! hand water for a couple more weeks till we can get the whole system going.

I would space your manifold so that you can add real valves later. will save you some time if you go that route. looks like they will be too close to screw them on the way you have it.
 

bbhaag

Diamond Member
Jul 2, 2011
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is it time for a garden tour thread?
we have plants under the row covers.

around here, and in the north the saying goes "if you are not afraid of a frost, you waited too long to plant" because the season is so damn short. our p80 last frost is like may 10 or something!! hand water for a couple more weeks till we can get the whole system going.

I would space your manifold so that you can add real valves later. will save you some time if you go that route. looks like they will be too close to screw them on the way you have it.
Haha not yet but a garden tour is getting close. I can't believe you already have plants under rows. That's awesome!

The spacing on the manifold will be every three feet. I just got done cementing all the crosses and connectors together so I lined them up on my work bench for the pic. Here's a pic of what is will look like when I get around to cutting more three foot lengths of PVC. I just cut to real quick for the photo.

So the hose from the holding tank will screw into the mesh filter and regulator at the bottom of the pic and then every three feet there will be two valves. So every 3,6 ,9,12, 15, ect up to 24 feet for a total of 16 individual zones. The reason for the three feet spacing in between rows is because we lay down weed barrier and straw to help control weeds and the three foot is the width of the weed barrier.
IMG_20210408_172709215.jpg
 
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bbhaag

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Alright one last update until I get the system up and running in real time. @herm0016 kinda lit a fire under my ass when he mentioned above that he already has stuff planted and growing in the ground so the other night I buckled down and finished the manifold.
I used teflon tape on all the threads for the valves so there aren't any leaks and one other thing I did was add some unions to the system to make fall storage easier. At 24 feet it was to bulky to fit into our 8x12 shed and I didn't want to leave it out all winter so now I can break it down and store it away more easily. I know this adds a few more failure points to the system but I think it's worth it.

Anyway, here's how looks when it's broken down. Pressure test was successful so now all I need to do is lay out the poly tubing and punch some holes for the drippers. I can't wait to see how this works when everything is hooked up. I'll be honest this project has kina ballooned in cost and time spent so I'm a little nervous.....
IMG_20210409_175725717.jpg
 
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