I am newer to pool ownership. I opened the pool a few days ago. Took out all plugs, lubed rings, cleaned sand filter etc. I turned on pump other day and everything seemed good. Water flow and filter pressure were functioning as expected. Turned off system and picked up some chemicals. I turned on pump last night and now nothing is coming through return jets. Pump has power and I checked skimmer and pump baskets but no clogs. I tried adding water to get prime back but nothing works. I did notice a broken union nut on my valve. Could this be problem? Seems strange that system started fine and now won't get any flow. If it is this nut, how do I fix it? PVC appears glued into pump. Do they make split nuts at 3"? Don't want to cut pipe as not experienced with plumbing. Thanks.