Bubbles from return

Not sure if this thread belongs here, but since I'm opening up my pool for spring....

I am getting some bubbles from the return into my 24' round AG pool. I have a 3/4hp Hayward Power Flo Matrix pump and a 150lb Hayward sand filter (both less than a year old). I am using flex hose.

I lubed the pump hair/lint trap o-ring with some silicone spray and made sure it was tight. I don't seem to have any water leaks. The bubbles become very numerous when I attempt to vacuum the pool. FYI, when I vacuum, I leave the filter set to 'filter'. I plug the vacuum line into the skimmer basket with an adapter. I make sure the vacuum line is primed with water before I make the connection.

The pressure gauge jumps every few seconds between about 10 and 15psi when I vacuum. When these jumps occur, I notice the flex lines all flail about like they're under high pressue. This happens about every two seconds. It makes a whoosh WHOOSH whoosh WHOOSH sound. When I stop vacuuming the bubbles diminish and the pressure spikes stop.

Any ideas? I really need to get my pool vacuumed. I unfortunately had some small holes in my winter cover that let a bunch of trash through.

Thanks in advance!!

Sam

Possibly the pump isn't primed very well, , or your filter is not completely filled with water. I had a similiar problem this evening opening up my pool, had to reprime the pump several times over because it keep using up all the water to fill up the sand filter.

Do you have a release valve on top of your filter? If so, open it up until you get a steady stream of water.
One thing I had to do last year on my pump was 'crack it open' where the adjustable metal band seals it and lube the o-ring in there.

Sam, this may or may not be the case, but sometimes the simplest answer is the right one --- try turning the vac hose around (switch the end in the skimmer and the end on the vac head. Many of the vac hoses have a swivel cuff on the end that attaches to the vac head, if you connect that end in the skimmer, it can suck air and momentarily kill the prime (ther swivel end isn't air nor water tight).

I will look at the vacuum hose this afternoon. Thanks for the replies. Here's something else I noticed:

I have tightened all fittings, greased all o-rings, etc. and my pressure now stays constant around 10. But I seem to remember that my lint/hair trap was totally full of water last season. In fact I would always have to open the top to make sure it was even full of water because it was so clear (no bubbles, etc.) that I thought it might be running dry. This year there is about 3 inches of air above the water line in the trap. I can see the water pulling in from the pool and churning all over the place.

If the trap is supposed to be without air, I could see why I would have bubbles in the return, because there is a lot of air in the pump.

Does this sound like the pump isn't priming? I tried filling the basket to the brim, but when I cut the pump on, it immediately drops a few inches I backwashed and rinsed the sand filter and the water is clear, so I don't think it is an issue with the filter.

Any other ideas? Thanks!!

Got it fixed. The flex hose from the skimmer basket to the pump had a hairline crack. Replaced it and it now works like a charm. Thanks for the help everyone!