There are several ways to clean well screens or perf. You can use chemicals like acid, I would check with Cotey Chemical about the best way to do that. Brushes, air jetting, high pressure frac, or even bailing are mechicanical ways to clean perf. None of these will help if the well only makes 30 gallons per hour. Cleaning only helps if the perf is keeping the water from getting into the well. Lowering the pump will usually help increase recovery rate, and will certainly help access more stored water.