Immediately after backwashing, I get decent suction on my vacuum and the returns which are pointing up are very vigorous except one return which occasional blows and doesn't blow as hard as the other two. After about 2 minutes of vaccuming which has the occasional leaf and some green gritty stuff on the bottom the pressure on my Sand filter rises to 30 and the returns are very weak. The one return doesn't blow at all. And I can easily break the suction on my vacuum in my skimmer. After I backwash everything works fine. I've sucked up far more stuff in a much dirtier pool in the past and didn't need to backwash every few minutes. I can't imagine that overwinter when it was unused until now it would be so bad. I had trouble getting my pool clean as we have had prolific rains and the pool almost over-flowed many times and had to be drained several times in the middle of a storm. I had a hard time getting my CYA stable and then all of the sudden I was throwing in 5 bags of shock and having it eaten up within minutes. It took soooo much shock to get it to shock level and hold. I don't know if that has an effect on the filter or not. But without vacuuming I'd still have to backwash every day. Overnight the pool filter pressure would climb to above 30. Oh and a few times the jets shot out very cloudy water. So..does that mean I need to replace the sand? Is this something that is safe for me to do? I mean I read a little on how to do it, but i'm a little nervous. Also I've seen a few say that its better to just switch to a DE filter. That sand is expensive and you end up saving money in the long run on DE. OH and I have no idea how old the sand is. We bought the home a few years ago. Thanks!