I am installing a 275 gallon rainbarrel with drip irrigation for 4 raised beds( each 4ft x 50ft). I don't really have the resources or time to build a platform for raise the barrel up for a gravity powder system. Therefore, I was going to try a solar powered pump. However, considering that my beds would require fairly long lengths of drip tubing I'm worried about the consistency of water out-put throughout the drip system. Do I really need to worry about pressure regulators, emitters, etc considering that I will be hooked to a pump designed for drip irrigation? any thoughts?
My IBC totes generally get a fair bit of algae in them during the summer months. My plants enjoy the extra fertilization that provides, but my guess is that the algae would wreak havoc on drip emitters and other things with tiny openings.
I've used drip systems with excellent results. The style I used had a limit of 25 PSI for the flow rate to work right. I dont think you'll have a problem with the pressure with a small pump. If needed, a pressure regulator can be installed in about a minute with a cost pf maybe 20 bucks.
I've got sandy soil. I set up my system with drippers every 2 feet. A 4x50 bed would require 2 rows with 25 tips each, or a single line down the center with foot long 1/4" tubing every foot. The advantage of the tips on the end of a foot of tubing is moving them around when a different crop goes in.
At the spacing above, the 2 beds would require 100 drip tips. With a flow rate of 1/2 gpm/tip, that vessel will drain in 5.5 hours of use. For my environment that would get me by for a dry week.
Before I used drip, I used clay pots with excellent results. I was in a D2 drought at the time and those pots would empty in a day or two. Filling them was getting to be a chore and the plant growth was making it hard to find the pots. I ran a drip line down the center of the beds with a drip tip shoved into the clay pot and a timer on the faucet. Every other day the pots would be filled automatically.
I did the math on flow rates, don't know where the notes are, but as I recall a 25 PSI supply would service around 250 tips rated at either 1/2 GPM or 1 GPM.
If you drained the entire 275 gallons across the 400 sqft, it works out to the equivalent of .8 inches of rain. About enough to last you a week in well drained soil, perhaps 2 weeks in a heavy clay soil.
John Wolfram points out the algae issue. I gave up on the drip system because of the clogging problem, and I was using city water at the time. An inline filter may be needed. Another option is an aerator and some algae eating fish.
Seed the Mind, Harvest Ideas.
We currently have two 275 gal. IBC containers which supply water to; the chicken house and for garden irrigation.
We control the algae issues by attaching two layers of opaque tarp material attached to the frame, this goes all the way around and over the top of each container, the resulting lack of light helps keep algae growth down.
Instead of using normal emitter type drip irrigation we have leaky pipe (algae doesn't clog it as easily as a drip emitter) running along the garden, the system is hard piped to where we need the water to go, which keeps loss of water down.
The chickens get water from this same system via a 3/4 inch CPVC pipe fitted with watering nipples, again to keep water loss to a minimum.
The chicken coop roof, which is 100 sq. ft., collects the water and will fill both containers in a 3 hour rain event. There is an initial bypass set up that allows the roof to flush off the first 25 gal. of runoff.
This keeps a lot of roof junk from plugging up the screens which keep out small junk. There are four screens not including the gutter cover. we start with 1/4" gutter cover and end with an unbleached muslin tank filter.
While our system is raised, it would work just fine with an on the ground set up with a 12 volt RV water pump (these operate at 40 psi) and are very adaptable to solar power with a backup battery.
Testing has shown that the small amount of chlorine needed (1tbs per 40 gal.) to keep algae at bay, would not hurt our chickens or garden plants, this amount of chlorine is far less than city potable water contains.
We only use this if we find algae is blooming in the tanks, so far in one year of use, we have only flushed the tanks after washing them out at the initial set up, all the chlorinated water was drained and the tanks flushed again after the treatment.
The opaque covers have kept any algae from becoming a problem, the water from this system is not used for human consumption.