I have a peculiar problem. I opened my older 16x32 in ground a few days ago (no main drain, one jet in deep end and one in shallow end). Water's clear, a little dead algae on bottom, no big deal, otherwise floor bottom perfectly clean, and went to manually vacuum out the algae. As normal, it takes about half a minute for the shallow end return jet to spit out the bubbles and then the vacuum gets prime and will suck water. So I began vacuuming. A half minute later the hose crimped up at the skimmer, i.e., the two sides came together so the hose was flat in a several inch section, and there was so much suction at the vacuum head that I couldn't even pull it off the pool floor. When this happened the sound of the pump changed because of course the hose wouldn't allow water to pass through it, so I pulled the hose out of the skimmer. I tried again and the same thing happened. I thought, is there an obstruction in the hose? Water runs freely through it so I don't think so.
I did make a mistake when I opened it and hope I didn't ruin anything. I took out the plug I had in the deep end jet but then got sidetracked and forgot to pull out the plug in the shallow end jet, the one that spits out the bubbles when I go to vacuum. The pool ran for about 24 hours before I noticed it and then removed it. Everything is running perfectly otherwise, have prime, pump is making the normal hum, a few bugs that seep through the skimmer basket are in the pump basket. Even though I backwashed the pool before I closed it for the heck of it I backwashed and rinsed again, and tried a third time and the hose crimped up again and I couldn't pull the vacuum head off the pool floor. This hose is probably 20 years old, can the plastic break down in a way that' s not visible to the naked eye and lose its necessary rigidity? I am dumbfounded. I guess the thing to do is go buy a new hose and see if the problem repeats itself? Thanks for any help anyone can provide.