I have noticed poor suction in the skimmer this year and maybe just never paid much attention to it so it could just be the way it works. But here's a question. When I open the lid to the pump basket the water drains out with a sucking sound leaving just a few inches of water in the basin. When I replace the lid and restart the pump the system primes itself within 45-50 seconds. Is this normal? I am wondering whether that is the source of the relatively weak skimmer suction.