If an herb has historical and clinical uses to treat anxiety, if it also is shown to reduce anxiety in mice, if it is also shown to be a potent GABA agonist in experiments with nerve tissue, and if I take it and feel quite relaxed and my palpitations cease, then my perspective as a scientist is that there is good evidence that the herb in fact does reduce anxiety." No, that's not the perspective of a scientist. It's the opinion of an herb user who wants to believe that a remedy works. That's why you'll never see a scientific study close with remarks by the authors saying "well, our evidence is only preliminary, but since this stuff worked for us we think that no further research is necessary." They'd be laughed out of their profession. There is no "EBM community" at odds with the scientific and medical community. The people who are most interested in optimizing medical care and making it as rational and effective as possible naturally are drawn to these principles, and work closely with physicians and hospitals to promote evidence-based care. When it comes to herbalism, there are basically three sorts of users (conveniently, all three are represented in this thread). First there are those who don't care about scientific validation of herbs (or at least profess this opinion). There are others who strongly believe in the value of good scientific evidence for the safety and efficacy of herbs before they'll use them, especially for more than minor conditions or as substitutes for mainstream therapies. There's also a large group of people who, like apollog, seem to want it both ways. They'll call attention to scientific studies that appear to support their position. But when it's noted that those studies are irrelevant to the topic at hand, limited in important ways and more evidence is needed, they'll fall back on testimonials, point fingers at other types of medical practice (the tu quoque fallacy), or deny the legitimacy of scientific inquiry that invalidates their arguments. This latter form of denial can be summarized as "Your science can never adequately measure my brand of woo." This is what has people devoted to sound scientific inquiry and rational medicine shaking their heads. They want advocates of all forms of health care to follow the rules by which the value of care can be established, including valid research and disciplined clinical observation. Unfortunately there are still self-styled advocates of herbalism who think the rules apply only when convenient. LOL.

For most systems, capping off some sprinkler heads will make the operating water pressure higher. The right way to build a system is with a pressure regulator before the valves, but that can add almost $100 of cost so most people skip it. Without the regulator, pressure will depend on the flow. Most water mains exceed the recommended water pressure for sprinklers. Mine comes in at about 110 PSI. Sprinklers like to run around 40 or 25 PSI. The reason it usually works is there are so many heads on a zone that the valve restricts the flow and brings the pressure down. When you cap off some heads, the pressure goes up. Many valves have a flow control option and if yours does, you can adjust it to bring the pressure back down to the optimal level. If your valve does not have flow control, you can implement your own with a gate valve in series with your sprinkler valve.

If the sprinkler is hooked to a hose which is hooked to an outdoor faucet, the problem could well be that the faucet is not/cannot open sufficiently wide to allow the water to continually fill the hose. A sign of this is when you turn on the faucet, wait a minute, and then turn on the sprinkler which will run properly for a bit before evidencing a gradually diminishing water-flow -- the sprinkler literally is not receiving enough water to run full-force. A blockage in the water pipe leading to the faucet will have the same effect. Unless you are very handy with plumbing, call a plumber to repair. A second possibility is a kink, hole, or leaky connector in the hose; any of which would have the effect of diminishing the water supply to the sprinkler. Check the hose to remove kinks; and all connections to be sure they are properly tight and non-leaky. A third possibility is simply that the sprinkler does not run as forcefully as you expect it to, due either to having a blockage within the unit, or as a matter of design (changeable only by changing the sprinkler itself). A fourth thought is that the well system cannot keep it's tank refilled as fast as the sprinkler is pulling the water. I'd consider this unlikely, but as a last resort, check to see if you can run an in-house sink faucet full force continually for 20 minutes without diminished pressure. (Conserve the water by attaching a hose to the faucet or otherwise saving the water for re-use.)

So we need numbers.... without them we can't help you. Let's start with the static pressure - what does a pressure gauge read when the water is off? What is the peak pressure? To find out, you need a gauge that will record the highest pressure - it's about 15 bucks online or at your big box hardware store. It will attach to your hose bib, laundry connection, or similar.