HELP looseing prime when vacuuming

[sisie5]

I just bought a new hayward 200 lb sand filter.my pump is a 1 H P 2 Speed.
everytime I go to vacuum the pool it does fine for about 3 min.then It stops sucking.I checked there is no leaks.why could be wrong.is my filter to large.
before I had a 100 lb sand filter didnt have this problem.but someone told me that I need to get a bigger sand filter for the size of my pool.
18x33 oval ABG.my pool looks awful and so far in the last week I have use
20 gallons of bleach.Any suggestion

[matt4x4]

What type of vac do you use? Barracuda style?
Are you getting a good seal at the skimmer connection?
Possibly something stuck in/blocking your vac head?
Could also be that you have a small air leak between the skimmer and pump, teh extra suction req'd to drive the vac can easily cause a small air leak to become more prominent to the point of inducing enough air to cause you problems with suction.

[sisie5]

I just use a vacuum hose hooked to the skimmmer.

[matt4x4]

Could also be a crack in the vac hose - try another hose first if you can borrow one from a neighbour or something....

[waste]

Check the vac hose, many of them have one cuff that swivels for attaching to the vac head, because it swivels, it's not water tight and if it's close enough to the surface it'll suck air and kill the prime.

[sisie5]

Well I did get another hose,still the same problem.I have never this problem until I changed filter.I 'm about ready to go back to my old sand pro filter.I can't get a grip on cleaning my pool.it is so green,and I have already in the past week dumped 15 gallons of bleach in the pool.im tried of hauling bleach bottles.Is there other way to keep a pool clean
I have seen on here something about salt.Can someone explan the method on salt,What kind of salt,and where do you get it.
Thanks for all the help