Why Timing Matters: When to Schedule Pool Opening Services in PA When Should I Open My Pool? We Say: Don’t Wait for 80 Degrees In Pennsylvania, many homeowners wait until late April or May to schedule pool opening services. By then, temperatures have already begun rising — and so has algae activity. At Infinity Pool Solutions , we often recommend scheduling your pool opening in March (weather dependent)  or early April. Opening earlier gives you a major advantage when it come