Gradual loss of suction while vacuuming

[PatL34]

I am new owner of a home with a pool and I am slooowly figuring this stuff out, with the help of this forum.

My problem is that I recently opened my pool and have been cleaning it but I am finding that within about 10 minutes or so of (manual) vacuuming I lose most of the suction. When I pop off the end of the vacuum from the skimmer I notice that the water just isn't being sucked into the skimmer at the normal rate. If I turn off the pump for 10 seconds, and restart it the flow rate returns to normal and I can go back to effectively vacuuming for another 5-10 minutes until the same thing happens. The suction is good enough that the vacuum remains connected to the skimmer, but it's not good enough to grab much dirt from the water.

I have checked some of the obvious stuff: the skimmer basket doesn't have much (or any) debris, and the sealed basket next to the pump is also empty of debris (but full of water as it is supposed to be). I also make sure not to introduce much air into the system when connecting vacuum. Lastly, I have backwashed the filter to see if that helps, and it did add better suction overall, but did not solve the problem of diminishing suction. I have the drain/skimmer valve set to full on the skimmer port.

Any suggestions would be appreciated! Thanks.

Background info:
- 20x40 Vinyl in-ground pool
- Sand filter
- One skimmer, one drain (on side) and one return

If you have the ability to vacuum to waste, you should be able to take the load of the filter. Any time you do a Spring start up, there will be a lot of stuff on the floor that may be invisible to the eye, but not to your filter.

If you had to use a lot of bleach to clear the pool up, then you may have stuff on the pool bottom that is blocking your filter slowly, giving alow flow.

By vacuuming to waste, you remove the stuff on the bottom, without it having to go through the filter.

Try this and see what happens and let us know.

Pat

(Matt4x4:- I'm not sure where the vac adapter comes in as he does not mention it in his initial post. If he does have one, then yes it needs to be removed to improve the suction.)