Losing Prime when vacuuming

I have a 33ft round pool w/ sand filter. Ran last year for first year(prior owner ran for 6 yrs) with no issues. Pump/filter runs fine at 17 psi steady state. When I put the vacuum skimmer plate on to start vacuuming, I lose pump prime every time. I force water into the skimmer plate to get the air out of the hose. I'm able to keep the plate under water while placing into the skimmer. Last year, I would usually lose prime once, but by the second time it would normally work. I tried last night about 20 times before I gave up.

The water does not totally recede in the pump skimmer(Goes down about half way). The suction line continues to flow into the pump, just not fast enough to build pressure and function the vacuum. Any suggestions?

I had this happen 2 days ago. What worked for me was to put the vacuum in the pool and then fill the hose full of water till it's flowing out of the plate, then slap it in the skimmer. It should keep a constant flow, at least mine did.

Welcome to the forum!

Check which end of your vac hose is on the vac head;)

Many hoses have a cuff on one end that will swivel and one that won't - put the end that swivels on the vac head. (I've seen this problem 100s of times, it's an easy mistake :) )

That's a good one Ted. I notice air being sucked in when that part of the vac head is out of the water when I do my steps but never thought it's so easy to mix up the ends.
On the original problem you have to be sure there are no tiny cracks in the hose above the water line. It only takes a tiny, almost invisible crack to let enough air in to lose prime. If you find a crack then you can dry the hose and use cheap electrical tape wound tight to seal the leak. Also use a few layers of tape. Depending on the condition of the hose you may get a lot of additional life from it.
Al

I ended up finding a hairline crack in the bottom of the skimmer housing. I kept noticing water dripping from it, but thought it was just splashing. Replaced that and now it runs like a champ. Thanks for the replies.