Ok. I was getting sand in my pool so I installed new laterals. I didn't see anything wrong with the ones I took out but replaced them anyway. I turned on the pump on rinse and forgot to open the return valves. i got tons of blowback sand out or the line that i plug my auto cleaner into. turned it off and realized they were closed. i backwashed the filter good and I'm seeing lots of sand in the sight glass when i have it on rinse. any suggestions??