We've got 2 330gallon rainwater tanks that we'd like to utilize to water our gardens for the summer with soaker hoses. The tanks are about 30ish feet from the gardens with basically no change in elevation. We attempted last year, and gravity alone doesn't provide the 10psi or so necessary for the soaker hoses to work. We've done an exhaustive amount of research on the internets and the only affordable (and simple enough for our lack of knowledge/time/skill) pump we've found (the Rule RainPerfect) is apparently no longer being manufactured. Anyone out there has success with other pumps? Or general advice?
I am no expert but 10 PSI os not much did you try raising the tanks by putting them on a platform? Or alternatively make a ram pump from the little flow you do have? I'm a newbie and no expert but that sprang to mind as I was reading your post. I thought I would reply because there is nothing more depressing when you are trying to learn and do than no one replying to your post... I hope it did not annoy! Good luck!
Suzanne Cornell wrote:I am no expert but 10 PSI os not much did you try raising the tanks by putting them on a platform?
For every foot of elevation, you only get about half of a PSI, so 10 PSI would require the tanks being up on a 20 foot tower. Based on the tank volumes mentioned, it sounds like IBC totes are being used to store water so while the pressure might not be that great, Gabe probably has a great flow rate through the 1.5" valves those tanks are usually equipped with. From what I have seen, it seems that solar is good at providing a little bit of power over a long period of time, but not particularly good at providing quick bursts of power unless you have a battery/charger system.
Gabe, instead of trying to increase the pressure, have you considered building a system that will work off high flow rate with low pressure? With a couple PVC pipes, fittings, and a drill you could make a pretty good irrigation system. Another thing to consider with the soaker hose is that the water in the IBC tote will likely have algae and other gunk in it which could clog up the soaker hose.
I found that ordinary drip tape and soaker hose could be run off of only 5 feet or so of "head" or elevation. Sometimes I had to ream out the holes in the drip tape a bit with a needle. I had barrels up on concrete blocks, and then later 300 gallon square caged plastic tanks up on stacks of blocks, braced here and there with wood and plumbed together with pipe to function as a single larger tank. On a second homestead with a little more elevation, I made cisterns with fencing, carpets, and plastic and set up siphons to run water downhill to gardens. 20 or 30 feet difference would run a small, low-pressure sprinkler as well as power water through a sun-heated coil of black hose and into a shower.
Thanks for your comments and insights! Indeed, my tanks are the metal-caged IBC type. The folks who sold us the tanks had kindly retrofitted them with a standard sized spigot. They're both full to the brim with water at the moment, so rigging it up to 1.5in PVC to increase flow will have to wait until August or so when they've emptied out. I like the concept, more so than being pump dependent. In the mean time, we may give the perforated drip tape a try...the guys who sold us the tank did mention that in their own gardens they had had some success with drip tape. As for algae management, what's y'all's approach to preventing clogs? has it been a problem in your systems? We've hand watered with our barrel water up till now, so it's a new consideration for us.