Damatano
Newly Registered
Posts: 1
Joined: Thu Aug 04, 2016 4:08 pm

Test reveals Uneven water in drip syst

Installed 1/2 tubing for drip system around my 1/2 patio for 17 plants with 2gph emitters with 1/4 tubing to the pots first stretch(closet to faucet) 8' with 5 plants works fine, second stretch 10' works with 7 plants works however the last stretch 9 ' with 5 plants drips very slow. I put a valve at the end plenty of water and pressure is released I am thinking of replacing the emitters to 1gph
Any ideas why I get uneven water released in the emitters
I am really green at this and need help

imafan26
Mod
Posts: 13962
Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

Before you install an irrigation system
1 test your gph. (fill a bucket with the hose from the faucet you are using. Turn it on full for 1 minute and measure the gallons you have collected at that time. I use a gallon can. Multiply the gallons by 60 = gallons per hour
if you have 17 plants each outfitted with one 2 gph emitter = 17 x2 = 34 gallon per hour. Divided by 60 minutes = 0.56 gallons per minute. Sounds ok
However most drip systems reduce pressure to a max of 20-35 lbs so as not to cause the system to blow out the emitters. It is a low pressure system. When you do the test, test it with the pressure regulator on the faucet. Make sure you also have an anti siphon valve in place attached before the pressure regulator to protect your water supply. You have to have a minimum pressure equal to the pressure in the regulator ( 20 or 35 psi) throughout the system for all the emitter to work. Once the psi drops below what the regulator amount, you will have drippers not working.

One way to get around the pressure drop is to reduce the size of the main line. Instead of using half inch tubing use 1/4 inch tubing for the distribution line. You will need an adaptor to fit on the regulator that has the 3/4 female faucet end and a 1/4 inch adapter to connect the 1/4 inch distribution tubing instead of the 1/2 inch tubing. You would use "T" connectors to run your side lines to the drippers. The down side is that you have a greater chance of clogging. I prefer to use end caps instead of hose clamps because it is easier to flush the system and it is the only way I can add to a system if I have parts from different companies.
Drip systems do get clogged over time usually from the salts in the water and the emitters have to be replaced.
https://www.amazon.com/Orbit-DripMaster ... B002BXTBM2

Other considerations. If you are running your drip tubing uphill to hanging baskets or a high shelf. There will be increased resistance in the lines from gravity so you cannot use as many drippers.

I would switch ot 0.5 gallon pressure compensating emiters and run the system for a longer time. If you have larger pots then you can use a few 1 gallon pressure compensating emitters. Another rule is that emitters need to be spaced at least 18 inches apart preferably 24. Soaker tubing is usually 18 inches between emitters. Resistance to flow increases with length so the emitters in the beginning will be spurting and the ones on the end will not have water. Maximum length is 200 ft but if you have low water pressure (like I do), running a shorter system is better. I have a timer installed on a manifold connected to my drip system. I have 6 zones. 2 are standard irrigation zones for grass and shrubs. The rest are drip zones. I had a landscaper install the system. It has higher pressure since it is tapped off before the line reaches the house valve which further reduces water coming out of the faucet. I also have installed in line shut off valves since one of my systems is too long to work with my low water pressure. I have to manually turn on the sprinkler and turn on and off the shut off valves to the two parts of the system. I have no pressure regulators in line and my house pressure is a ridiculously meager 38lbs. Try flushin a toilet and taking a shower with that.

Usually the seat of the pants way to determine the maximium load is to run your main line and put your first emitter on the end of the line. next install the first emitter closest to the faucet and go back and forth from the front to the back. Check periodically to make sure your end dripper is still flowing. If you put in one too many sometimes all of them stop working. Then you put in a goof plug and you know you have reached your limit.

https://www.irrigationtutorials.com/drip ... -and-more/
https://www.savingwater.org/cs/groups/pu ... 009355.pdf



Return to “Water Gardening”