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Springfield, OR

I'm considering using a gravity fed system to irrigate and fertilize my 4 plant patch this season. I have access to a black plastic 300 gal tank which I can elevate about 5 ft off the ground at the base. This should give me 2-4 psi at water level in the tank. I plan to use perforated garden hose buried around the base of each plant in a spiral pattern. Does anyone have experience with a system like this and do you think I'd have enough pressure to distribute the water/fertilizer?
Thanks for any comments or suggestions.

1/15/2005 10:51:23 AM

Indiana

I had trouble getting enough flow out of the garden hose the holes arent big enough. This year im gonna try adding a 12 volt RV water pump and battery inline to see how it will work.
Steve

1/15/2005 12:01:50 PM

Eugene, OR

Hey Mcjim. I'm also an Oregon grower and I used a gravity fed system this past year. 5 ft of elevation will give you just over 2 psi of pressure on paper but it will end up being more like 1-2 psi with all the head losses in the fittings and lines. How tall is the tank? If I'm thinking about the same stuff you're talking about, I don't think 2 psi is enough to run that type of hose. I've never actually tried it though! Of course, your pressure will be higher when the tank is full but it doesn't make much sense to have a 300 gallon tank when you only have enough pressure to drain 150 gallons from it in a reasonable time.

If you're looking to run that type of system, an inline pump will get you all the pressure and flow you need. Another option to consider is t-tape from Dripworks down in Cali. They claim it works at pressures as low as 2 psi while still getting decent flow rates. I used a 10 ft high tower with lines spaced 1 foot apart and it took about an hour to empty the 240 gallon tower. 4 gallons per minute isn't great flow but it kept the soil at a nice even moisture level while watering.

I ran all my ferts through it and didn't find a single clog after pulling the lines up this fall. 240 gallons wasn't quite enough capacity for 4 plants though! Hope that helps, Brian.

Have you joined the PGVG yet? If you haven't, I HIGHLY recommend it! www.pgvg.org

1/15/2005 1:54:19 PM

Montoursville, PA

Brian............Nice report. I agree and have done almost the same set up. My humus is above 15%. My T-Tape lines are eighteen inches apart about four inches deep. I found that 110 gallons a day with no help from mother nature maintained a nice moisture level. The time to drop it from an eight foot high tower was about one hour and twenty minutes to a one thousand square foot patch.

I work it manually but could, with a bit, of Indiandoity turn it into a state, of the art automation. A head tank fill valve would work fine with a bit of placement on the side of a barrel experimentation.

1/17/2005 7:16:37 PM