Too much suction !!

[JohnT]

Hope I am posting in the right place--
Have an IG pool. have been having problems with algae so have been shocking and vacuming a lot. Problem is now I have too much suction and the vacum wont move. I have to pick it up to move to another spot. Started about 2 wks ago--before that no problem to vacum. For some reason it just wont roll. Any suggestions anyone????

Check the brushes for wear (assuming it has brushes). Once they get down so far, the head will start to stick to the bottom.

[duraleigh]

Karen,

I doubt it's too much suction. Your flow thru the system would have to had inexplicably increased for the suction to go up.

Actually, if it was too much suction, that is easy to fix by simply restricting one of the ball valves on the pressure side of the pump. Your filter pressure will go up, and the flow thru the system will decrease resulting in less suction at the vac head.

[tenax]

duraleigh, i'm no expert, but can only go by experience that when my filter pressures rises, my suction increases, rather than decreases. that is factual experience. i can definitely tell the suction has increased?

[cwstnsko]

That seem counter-intuitive. It'd be like saying that your vacuum cleaner has more suction with a dirty bag than with a clean one. To have more suction, you need higher flow rate. Dirty filters cause a lower flow rate and should result in less suction

[mas985]

There is only one condition where this can be true and that is with a 2 speed pump. Going from low to high speed, you are effectively changing the HP of the pump so you will see both a rise in PSI as well as suction.

Assuming the same pump and speed, and the PSI rise is due to a dirty filter, solar or other return restriction, higher filter pressure = more head loss which means less GPM. Less GPM = less suction. This what hydraulic theory dictates and what I have confirmed through measurements.

If you had a suction guage on your pump, you would see it drop with higher filter PSI. However, just the opposite happens when the PSI drops so perhaps this is what you are experiencing.

[karenkr]

Ok guys ---thanks for all the input but honestely we do have too much suction. Hubby actually bent the pole trying to get the head unstuck. Also you are talking to a real dummy here. As you can guess this is our first season of maintaing our pool on our own so we have lots to learn and we sure do appreciate your help.The pump is an AquaTool Sand filter,Stay -rite
dyna Glass with RPM of 3450- tank says 300lbs. I have no idea about what I just wrote--that is just what it says on the tank. Thought maybe it might help you guys.
To vacuum we put this black disc in the skimmer and attach the hose filling it with water. The head is attached at the end of the hose that we put in the pool. Keep water pressure about 15--if it starts to rise we backwash. The only thing we have not been doing is rinsing MAYBE that is the problem!! Could the sand be too dirty? Water is dirty when backwash but clears right up in few min. Should I be rinsing after I backwash??
Duraleigh you suggested restricting the ball valves on the pressure side of the pump---How do you do this (told you I was a dummy)

Please keep the suggestions going--ALL help is appreciated

Thanks
Karen

[duraleigh]

Karen,

You should have a valve/valves on the pipes that come out of your filter and take the water back to the pool. If you partially close that/those valves, your pressure will rise on your guage and you will have less flow throughout the entire system....that means less suction.

I'd stop closing the valve when the pressure got to 25...maybe 28 max.