When the plumbing on our pool went in, the pressure was slightly under 40 PSI (maybe 39 PSI). It's been about 3 weeks, and I noticed the pressure is new around 36 PSI now. The pipes are slightly covered now (to allow the workers to move around more easily) and the temperate in our area has dropped within these last 3 weeks (maybe 5-10 degrees during the day and more at at night). Would that account for the difference in pressure or should I be worried about a potential small leak? I'd figure if I had a real leak the pressure would have dropped considerably more.