I used to have an account a few ago, this site helped with the change from bauquacil to bbb. I am currently running a hayward s200 sandfilter with a hayward powerflo ex pump on a 24 foot agp. Everything was fine last season, this year on opening, water was very green, I bleached and bleached and its now cloudy. My problem is my return flow to the pool gets very weak, so I backwash the pump for up to a minute, rinse, and filter. Water return to pool is good for a short while then weakens again. I changed sand, it was nasty. After sand change, I was careful to add water first and slowly add sand to protect laterals. I put pump on backwash and Im blowing a ton of sand out my backwash. I rinsed and then am now on filter. Same problem, I got good return to pool for awhile then it gets very weak. I can turn off pump for a second and plug back in and get good water flow. I am baffled.

Sorry for the long post, but in short my issues are:
1. Why is my new sand blowing out backwash
2. Why is my water return to pool getting weak so fast