Hi Geoff, In regards to the foot valve and filtration, yes, I would suggest the use of a filter, why? Because small bits of algae, sand and other debris over time will build up in the valve diaphragm. The sprinkler heads can pass a small amount of debris fine (they have filters under the nozzles) it is the valves you should be most worried about. For your application, the use of a disc filter would be most appropriate. Disc filters use a series of screen discs that the water is forced through the amount of filtration is measured in mesh. The recommended mesh for a irrigation system is 100 mesh. Most disc filters need to be cleaned on a annual or bi-annual basis by unscrewing the filter top and hosing it off well. Disc filters are not as easy to come by as their cousin the screen filter. However a trip to a local irrigation supply house, like Ewing, should produce some nice results. Oh, a regular irrigation valve should NOT be used on a system running off lake water. You need a "Scrubber valve" which incorporates a very heavy duty diaphragm and stainless steel hardware (like molded stainless bonnet studs for easy service) The model is suggest using is the 100-PEB from Rain Bird. Once again, not going to find it at home cheapo, go to a irrigation supply house. About the sprinkler heads. I would suggest going with the same brand of sprinkler heads as long as they are not orbit or toro. Hunter makes a wonderful rotor as does Rain Bird. I will assume you have Hunter PGP rotors (they are very common) and they work great, some of the guys have complained they stop rotating as you mentioned, but it's luck of the draw. Because of the rotating issue, many have switched to the Rain Bird 5000. I haven't tried the 5000 but Rain Bird makes excellent products so it couldn't be half bad. Both the 5000 and PGP come with a nozzle tree and adjustment key. You can match the numbers on your old nozzle with the new when changing it out. And again, go to the irrigation supply house. Moneypenny: Any irrigation system running from a lake should incorporate disc filtration and scrubber valves. These will pay for them selves over time and will give you peace of mind. The pop-up rotors are personal taste but I like the PGP's just fine. With a filtration and care you will be good to go. Don't opt for the cheapest stuff out there, you get what you pay for and I can say this from experience. Cheap brands include: Orbit and Toro. Don't go to the big box stores like home depot, they won't carry the products you need, it's the professionals choice and why not support the local business? Links to products mentioned in this tutorial and other helpful links: Arkal-Amiad filtration: Mfrs. of manual disc filters. 322 Rolling Hill Road Mooresville, NC 28117-9920 http://www.arkal-filters.com/pro_manual1.html Rain Bird Corp: Mfrs. of high quality irrigation components. Rain Bird Corporation 1000 West Sierra Madre Ave. Azusa, CA 91702 http://www.rainbird.com/landscape/products/valves/PEB_PESBseries.htm Irrigation tutorials/help: Jess Stryker, professional irrigation system designer with 30+ years of experience. http://www.irrigationtutorials.com/ I do not endorse any of these manufacturers or people. I simply know good products.

Two mechanical solenoid switches and their valves, a better timer/controller and having to dump unused energy (with a cool venturi) instead of a single timer and airstone if you wanted? I could see it in a big fishtank needing currents, with fish *depleting the DO* but not in a little reservoir with a waterfall. Don't mind naysayers and keep at it Definitely! It could be a better mousetrap that will leave us all eating crow, far reaching in hydroponics as this innocuous thing that so changed the world! I don't think either of us has enough performance specifications on both system configurations to them justice. There are way too many assumptions in play here that have not been tested head-to-head. Let me randomly list some of them. The electromechanical lifetimes of both actuators under continuous operation. The possibility a solenoid will stick, or that the valve it controls get clogged, etc. The electromechanical lifetime of a magnetically driven pump where power is cut and connected at high daily frequencies. The electromechanical lifetime of a magnetically driven pump where load is switched, depending on mechanical switching speed and pressure differential stress through each switch of load. Will the return waterfall + the Aeroflo type delivery will get you the same DO for the dripping roots with a simple return waterfall from a DWC spray system like AeroFlo2 as your dripping roots will get, or do better? Your pump is warming the reservoir more until you get the sizing very fine tuned. All that extra runtime you are dissipating by not turning the pump off is warming the reservoir and lowering the ability correspondingly due to the inverse relationship of DO(T). I didn't realize you had already studied the Aeroflo, but it makes a lot of sense that having one got you thinking along the lines of your design. I personally would spend all the power I had at my disposition in getting a finer mist. The finer the mist, the cooler the water and when it goes splat on the roots, the greater the DO as well as absorption, *I believe*. Experimenting would be fun though and you will probably gain a lot of experience by the time you go through it all. In the ignorance of both of us, we need the spec and ageing tests of the candidate pumps. An electrocardiogram of the power amplitude during switching vs. what happens with the surge from off. I wouldn't be surprised if both type of operation caused a similar integration of the power pulses (power 'jerks'). I'm sure I'm off on some of my assumptions but there are many. For that reason I appreciate the AeroFlo as a very dependable system, with the caveat that I've never owned one and just am impressed by their keep-it-simple design. You sound like you have some engineering talents, so I hope you know I’m just being your sounding board and am impressed you are tackling something as cool as this for which I have plenty of theoretical hurdles. Best of luck, and think ‘patent’ while you’re at it, I would!

Nan, I donÂt know that I have one specific answer to your question but I will share with you what I have done to attack this issue over the last many years. We did install our entire system ourselves which just like landscaping it really isnÂt the sweet equity that is all that important but the design experience from the sprinkler guy that counts. Of course dh and I felt no one else could do as good of a job as we could because we intimately understood the needs of our property much more than any one stopping by to "take a look at the job" ever could. Frankly we discovered we did a pretty good job but the needs of our property as plants were moved or were actually were given a chance to mature were ever changing and just like many chores/tasks I would rather hand over the yearly maintenance of this one to someone else. I have a system with many different zones as well as different types of watering. The different types for me are soaker, lawn sprinkler (with many different types of heads), direct tubing (in the woods). The name brand of materials I have used over the years has been Turo which you can buy at any plumbing supply store. One of the largest costs to a sprinkler system is having the back flow preventer installed by your plumber. You will also need to rent the tool that cuts your lawn to allow you to lay the piping. Once a year in the fall I need to have the guy come and blow out the pipes with a compressor to prevent winter damage. I have also depended on him to come and trouble shoot the system after a brown out or extremely cold winter. I have also installed a sprinkler system at our beach house in southern Fla. using parts from a Home Cheapo and I will tell you it was a disaster that needed constant maintenance. All and all I suppose when ever I get the sprinklers guys bill I wonder why it is so small and I am happy to pay it. kt

tulsacityfarmer, I start out with about 44lbs. of pressure. The pressure will drop with each hole you have in your pvc system. The most pipe I could run ( feeding thru a 5/8 hose) was about 150 ft. The more slope you have the less pvc pipe you can run. ( I like running about 80 to 100 feet at a time) At the old house I ran a 3/4" line from the well to the garden which gave me much more flow, and I could run more more feet of irrigation tubes. My system is glued together. I started out using my system about 7 or 8 years ago and it is not all the same because I experimented as I started using it. I started out with high pressure and just using the tubes in areas where disease was a problem, I also tried using 40 and 50 foot tubes with holes drilled from 8 to 15 inches apart. I moved into the house I live in now about 4 years ago and my garden is much small now because I have very hard tight soil, plus now I have to buy my water. I think you will find that with about 45 lbs of line pressure you can feed approx 300 1/16 dia holes, at that time you have dropped to well under one pound of pressure. If your lines are not some what level you wont be getting satisfactory flow in all areas. You can increase the flow by using ball valves with larger opening in your feed line. I have tried running the tubes above and below the mulch and I think I like above the mulch better because if I have the holes in the side or top of the tube I can see if I have a hole plugged and the mulch breaks down faster if it stays damp. I know this is a lot more than you ask for, but I get carried away some times. I think you will fine that all our systems are a little different, but all get the job done. The largest problem you will face is too much slope on your tubes. In some cases I have driven stakes along the row and ties the tubes to it to make them more level. Otherwise you will have a 1/2 inch high stream at one end of the tube and a 6 inch high stream at the other. Larry