Drip Tape Questions.

Hawkins

Hawkins

Basically I need to know how I would go about figuring out how long to run drip tape.
 
I have 12' spacing, 0.46 GPH 250' for tomatoes, 600' for peppers, 350' for melons. I know what is required for each plant, but have no idea how to figure out how 1" of water a week translates to drip tape.
 
Don't worry about 1' of water a week. Water when the plants need it and make sure to put a shutoff at each driptape off of the mainline so you can control each row.
 
Where did you come up with 1' of water a week? That seems excessive.
 
which drip tape are you using?

the manufacturer will specify the rate. examples: https://www.dripdepot.com/category/drip-irrigation-tape

for ones with emitters you do (convert 100ft to inches) (12*100) / emitter spacing (example 8") * emitter flow rate (example .25 gph) = 37.5 gph
so if you are running 1200' ... 12 * 37.5 = your total flow in an hour.

if they just give you flow rate @ psi @ lenght then its usually like .25gpm @ 100ft
so convert gpm to gph = .25 * 60 then * 12 (because 1200') = 180 gallon per hour
 
1" sorry not foot, they would literally drown. haha. I'm more trying to figure out when they need water how long to run it for.
 
Rajun Gardener said:
Don't worry about 1' of water a week. Water when the plants need it and make sure to put a shutoff at each driptape off of the mainline so you can control each row.
 
Where did you come up with 1' of water a week? That seems excessive.
Click to expand...
 
 
It's gonna depend on if you have the plants mulched/plastic or not and the type of soil on the time to run it. I run mine about 1.5 hours every other day if there's no rain. All three of those plants will require a different amounts of watering so just check the soil and water for an hour when it's dry. That's why I mentioned putting a shutoff at each leg of the system. You'll get used to it after a few times you water, drip tape puts the water out slow and it sinks in the soil more than you think compared to hand watering or a sprinkler system. 
 
juanitos said:
which drip tape are you using?

the manufacturer will specify the rate. examples: https://www.dripdepot.com/category/drip-irrigation-tape

for ones with emitters you do (convert 100ft to inches) (12*100) / emitter spacing (example 8") * emitter flow rate (example .25 gph) = 37.5 gph
so if you are running 1200' ... 12 * 37.5 = your total flow in an hour.

if they just give you flow rate @ psi @ lenght then its usually like .25gpm @ 100ft
so convert gpm to gph = .25 * 60 then * 12 (because 1200') = 180 gallon per hour
Click to expand...
 

That's what I went with from Drip Depot. 12" spacing, .46 GPH 15mil, I also got a 10psi reducer. I'm not worried about how much is actually going into the field as far as gallons go, just more worried about how to figure out the timing to get enough water deep enough. I know different soils vary, but I'm not sure how to figure that out. My soil has a bunch of sand and clay in it, and not much organic material, it's going to take years of build up the organic content.
 
Rajun Gardener said:
It's gonna depend on if you have the plants mulched/plastic or not and the type of soil on the time to run it. I run mine about 1.5 hours every other day if there's no rain. All three of those plants will require a different amounts of watering so just check the soil and water for an hour when it's dry. That's why I mentioned putting a shutoff at each leg of the system. You'll get used to it after a few times you water, drip tape puts the water out slow and it sinks in the soil more than you think compared to hand watering or a sprinkler system. 
Click to expand...
 
It'll be zoned off, melons on one mainline, tomatoes on another, peppers on their own, etc. They will be planted in Dewitt weed barrier, with the drip lines on top. Ideally I could set it up to water based on the weather for the week programmed into a 4 hose controller.
 
 
yeah it is very variable based on your soil (porosity/drainage), environment (sun, wind, humidity, rain, etc), and plant size (bigger plants drink more)

it is better to do a deep watering than tiny watering that only soak the surface (you seem to understand this)
I find 1 gallon gives them a good soak. for me so that's 2 hours for your drippers?

When seedlings they will require much less as they are still developing root systems. Also in the spring it is not as hot yet.
i find that watering every 3-4 days is good. (if you have controller, set to every 3 days or like monday thursday)

In the summer and the plants are bigger
every day
 
So my well will fill a 5 gallon bucket in exactly 1 minute, so that's 300 GPH, I'm really confused with how to do the math to make sure it will run the 0.46 or if I need to get a slower rate.
 
You're making it harder than it needs to be. It'll work with what you have and you need to test it to see how it works best. 
 
How are the rows set up, all in a single row or multiple rows and how long are those rows? Also what's the distance between the rows?  What size tape and what size is the main line? All these things are need to figure out flow and supply from the well.
 
 
I have a well too and it works fine with 3 100" rows and 7 40" rows. I don't think you can run the whole system at once because of drop in flow rate and pressure.
 
 
 
Edit" I run a 25psi reducer without problems. Were you told to get a 10psi reducer?
 
Rajun Gardener said:
You're making it harder than it needs to be. It'll work with what you have and you need to test it to see how it works best. 
 
How are the rows set up, all in a single row or multiple rows and how long are those rows? Also what's the distance between the rows?  What size tape and what size is the main line? All these things are need to figure out flow and supply from the well.
 
 
I have a well too and it works fine with 3 100" rows and 7 40" rows. I don't think you can run the whole system at once because of drop in flow rate and pressure.
 
 
 
Edit" I run a 25psi reducer without problems. Were you told to get a 10psi reducer?
Click to expand...
 

My rows will be 25' each on the peppers and tomatoes, 70ish on everything else. I got the 10psi because that's what it says to get for the drip tape.  Each row is about 5' apart. The dripline is 3/4", the mainline is 5/8". I just want to make sure I get the right stuff, I hope to get a few years out of it before having to replace it. I plan to run in sections as needed.
 
Yeah I used the calculator, thanks! Not sure what they call high flow and low flow but for what I want either will be fine. I actually decided to plant long ways instead of short. So I'll be doing 100' rows instead of 25', mostly because it's less material used for mainline and fittings, although I all ready ordered them.
 
Rajun Gardener said:
Call who you bought it from and tell them all that and I would bet they will get you straight. OR use that calculator above and figure it out.
Click to expand...
 
 
Hawkins said:
 
It'll be zoned off, melons on one mainline, tomatoes on another, peppers on their own, etc. They will be planted in Dewitt weed barrier, with the drip lines on top. Ideally I could set it up to water based on the weather for the week programmed into a 4 hose controller.
 
Click to expand...
 
If you can put the dripline under, you'll have better results, I did dripline over dewitt last year and every time it got hot, the dripline expands, kinks up, and you gotta straighten every damn line each time you water.  Even staked down every 6', the line would expand / contract several *feet* over a 100' run, enough to cause it to kink like crazy. When cold water hit it  on a hot day, it'd contract (visibly), but more often than not, it'd kink somewhere along the line at a ground stake as it shrunk.
 
If you put it UNDER the ground fabric, preferably buried alongside the plants an inch or so down, it won't do that. It'll stay cooler in contact with the ground and not sun-baked, so it shouldn't move around as much.
 
If you get a line that gets clogged or whatever you can always run a replacement on the surface.
 
Also the dewitt ground fabric does not let water through very easily. It is water permeable, but when it's dry it doesn't tend to let water through. When it's wet, water flows through freely, but whenever I'd turn on the irrigation the driptape would emit and I'd get puddling in low spots; water would just run right down the ground fabric and lay in a pool.
 
I had much better luck with flat (not crowned) rows with it. Any time you spend making the ground flat, is time well spent, if you can get a nice straight plane.
 
Also dewitt fabric holds LOTS AND LOTS AND LOTS of moisture in the ground. You will not need to water nearly as often as you think you will need to, or have in the past, because water will not evaporate through it.
 
On stuff with low hanging / heavy fruits, it's wise to spread straw over the fabric. The black fabric will reach temps of 140F or higher in sunlight. More than enough to burn fruit.
 
Also makes harvesting or maintenance a bitch when you are kneeling down and dealing with first degree burns everytime a piece of exposed skin hits the fabric. :)
 
Also make sure your regulator and water supply are up to the amount.
 
I got a 12psi 2" regulator (4 spring) and promptly blew out driptape when I didn't have enough emitters. Those regulators DO NOT regulate pressure if you fall below the minimum GPM, as there's not enough water flowing for the springs to really do much of anything. I had to run a LOT of tape before I could get 12psi reliably out of the 2" netafim regulator. (Like, 2500+ feet at .45gpm/100')
 
Then I found out my well couldn't deliver the amount needed without running dry and belching air. Each zone on my 2" regulator had to be over 12.5 gpm, or else pressure wouldn't clamp down and I'd blow out tape. So I ran double tape along 15 100' rows per zone (30 runs), minimum, to reach 13.5 gpm. My well would run that for about .. oh, 15 or 20 minutes, then belch nothing but air.... I'd have to let it recharge overnight and hit it again the next day. Meanwhile the well would run forever at 5gpm so I ended up putting in a 1,200 gal transfer tank and filling it each day with a garden hose at a few gpm (took about 6 hours). 
 
Anyway this year irrigation is a "thing" - I gotta sort it out. I had a new, deeper, bigger well dug last  year 140' deep (in to the aquifer) that can pump 80gpm continuously.
 
 
250' for tomatoes, 600' for peppers, 350' for melons
 
That's not much so you should be fine with your 5/8 headers. Peppers @ 600' at .45 gpm would be 2.7gpm, 250' for tomatoes 1.125 gpm, and 1.575 gpm for the melons. 5.4gpm max.
 
You'd be fine with this; https://www.berryhilldrip.com/Pressure-Regulators-by-Netafim.-3-4-up-to-3-in-Size.-Plastic-and-Brass-Regulators.html
 
Get the low flow as if you just run your melons or tomatoes you'd be WAY under what a larger regulator could regulate. (Remember if you go "below" minimum flow rate it probably wont' regulate properly and you'll blow out drip tape)
 
GET PRESSURE GUAGES.
 
https://www.berryhilldrip.com/PR-TAPE-30-Pressure-Gauge-on-Drip-Tape-Fitting-for-reading-pressure-at-the-END-of-your-rows..html
 
Put one at the end of your first row and one at the end of your last row in each zone (especially if you have any slope at all)
 
And one of these on each of your laterals
 
https://www.berryhilldrip.com/PR-STAKE-30-Gives-accurate-reading-at-the-Beginning-of-your-lines.-Barb-to-Poly..html
 
Also don't bother with "end row fittings" (the terminator caps). Just tie the dripline in a knot at the end.
 
Much faster and those persnickity frigging terminator caps can go to hell. (If you don't cut your dripline perfectly square and do it *exactly perfect* - e.g. no emitter along the barb - they will leak like crazy)
 
 
TrentL said:
Also don't bother with "end row fittings" (the terminator caps). Just tie the dripline in a knot at the end.
 
Much faster and those persnickity frigging terminator caps can go to hell. (If you don't cut your dripline perfectly square and do it *exactly perfect* - e.g. no emitter along the barb - they will leak like crazy)
 
Click to expand...
 

For the ends of the drip tape I was planing to use zip ties and stake it in place. I've been debating on over or under the fabric for awhile, I'll take your advice and go under it for sure. I won't be able to bury it, it'll just be on the ground before I put the fabric down.
 
Also I will be getting a few pressure gauges for sure. I'll check into the regulator and see if mine works, I have to get some more because I only bought one at the time didn't know I needed one on each line when I made the order.
 
For ends I cut a 2" piece of tape then fold the end over a few times and slide the 2" piece over it to seal it and it works great. 
 
Yes, You should put the tape under the material you're using but it still may kink if the covering isn't tight on the row. If possible use some type of mulch to keep the heat off the plant roots. Like Trent said it gets hotter than you think.
 
You should only need one regulator that can be picked up at Home Depot in the irrigation section. They might not have more than one PSI rating but I use the 25 without problems. 
 
I'm not sure why you would need a pressure gauge. You'll know if it works or not by the moisture in the soil and the amount of water coming out of the emitters. 
 
Pressure gauges are there when you first run it to make sure everything is working correctly. If you exceed the rated PSI it'll blow out, and if you've got dripline buried under row cover, that's bad. With pressure gauges the first time it's fired up, you can have someone with their hand on the off valve while you keep an eye on the gauges as pressure ramps up.
 
After that, it's not so important, but when you are first getting everything set up, it is.
 
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