Roscodagama

I appear to have a leak coming from the weir (filter housing) of my seven year old Envoy. The one filter tube provides a suction for the filter marked with a gray cap. I suspect this is where my leak may be coming from. A while back I was cleaning the tub and peeled some caulking from around the base of the gray tube. What is the best caulking to use? Should I need caulking under these filter tubes.? The corner of my tub has a puddle of water on the inside which constantly weeps onto my patio. I first thought it was condensation from my cover until I looked inside today. If I do have a crack in my weir does it need to be repaired with Fiberglas or can I caulk it? Comments appreciated. Thanks.