I hooked up 18 sprinklers to 1 valve and lost pressure? What do I do? I have 3 valves in the front. First valve has only 1 huge sprinkler and medium size sprinkler hooked up to it. The second valve has 18 valves hooked to it and I lost pressure (These valves were the small valves though - 18 of them and I thought it would be okay)???