Gradual loss of suction while vacuuming

[MassAttack]

Thank you - that's a lot of good information and advice. While I was able to pretty much rule out leaks, there could be more than one cause to my problem. I did find this morning that backwashing more seems to have helped a lot. After backwashing I was able to vacuum for nearly 30 minutes before losing suction. Even though backwashing seems to have done it for me, I will keep all the other advice in mind too. Next year when I have a lot dirt early on I will vacuum to waste, and at some point I will also try bypassing the skimmer basket.

Thanks again.