Since you're using anti-siphon valves, I assume you don't have a backflow prevention device between your valve manifold and your main supply line. The anti-siphon feature of your valves is intended to prevent possibly contaminated water from being sucked back into the main line. This method of backflow control is now generally viewed with disfavor, and may not comply with applicable codes. If the valve is not positioned at the mandated height above the sprinkler or drip line, the anti-siphon feature is defeated. On the bright side, a simple $10 backflow preventer is usually all that is required for a soaker hose or drip line, and when you open the valve, the water will flow. You will also need an inexpensive pressure regulator. Putting this together may be a bit tricky, and you will need to bear in mind the incompatibility of hose threads and pipe threads as you select the requisite components.

I don't know if the valves came with knobs and the installer stole them...somehow I doubt that. Never gave that part a lot of thought, actually *smile*. Pliers are fine with me. I suspect that I can open the valves up, but without specific instructions with a diagram, I never know if I can get things put together as they are supposed to be.. I'm currently working on getting a repair guy over to replace the valve, but he's as elusive as most contractors. Doesn't seem to answer new calls unless he's idle, apparently. Not a lot of irrigation system repair guys in my area of the world. Anyways, not sure what I'm going to at this point. I don't want to take the valve apart myself unless I have good instructions and a replacement valve (lesson learned from my spotty past history trying to fix plumbing problems). I guess my next step is to find a replacement Irritrol valve. I think that they just screw onto the riser pipe, and then there's the pressure reducer and Y-filter, and of course the waterproof wirenuts *smile*. Details, details. .

One suggestion is to find a sprinkler head you don't need (like a popup sprinkler used for shrubs that are mature enough that they no longer need irragation) or you can install a new 1/2" outlet to your existing system. Then all you need to do is attach a drip head conversion kit. It allows you to run up to eight 1/4" microtubes from the single head and you can regulate the flow/pressure to each tube. You can buy the converter at the big box stores. I've used them for years and have had no problems with pressure. I've included a link to the conversion kit sold on the Drip Store. Here is a link that might be useful: Drip Store Head Conversion Kit

Thanks for the suggestion! I'm not sure I fully understood however and I should clarify that the PVC pipe would be in the ground, not above. I think that you are suggesting is to attach a tee to the water source (in this case the PVC pipe) and then on one side of the tee, install a hose bib for the garden hose. The hose bib would allow me to keep the hose turned off when I want to water with the drip irrigation but wouldn't the drip irrigation still run when the hose is on? I think the concept of installing two valves from a tee splitter would work (one to the drip irrigation and one to the garden hose) but if possible I would prefer to keep is as a single switch. Since this is likely to be located in the ground, I was hoping to minimize the space required and if possible fit this in an in-ground valve box. Thanks!