Air in Sand Filter (Hayward)

Our sand filter seems to keep getting air in it, but we're not sure why/how. It will stop circulating after a fairly short period (sometimes an hour or less), we bleed out the air or backwash it and it works a while then does it again. The pump still has water and doesn't lose it's prime and there is no leaking from any of the hoses or connections. Any ideas why it might be doing this? Thanks!

Pam

You almost certainly have a small suction side leak. Try tightening the pump basket lid and checking the drain plug in the pump basket.