Another 'sand in pool' thread?

Hopefully my predicament will assist others. Just replaced my pool, am still using 2yr old hayward 21" sand filter. Reloaded with new sand and now I have a small amount of sand shooting out right when the pump starts. Not a lot, because the "a lot" already dumped into the pool the first 2-3 days. We should all know about cracked laterals and center pipe (not as common) but what else is there?
1. Your spider gasket on the multi-port valve on top of your sand filter. In my experience these should last 3-5(?) years. When I replace it I'll update this post.
2. Amount of sand in your sand filter in relation to your pump. Yes, this is a biggie I'm finding most people overlook. This is the 2d time I've put sand in this filter and this is the only time I've used the amount stated on the filter; 200lbs. I think with most above ground pools; and some in ground; the pump size can 'flush out' sand until it gets to a point where it wont force anymore sand into the pool. 2yrs ago I put 150# in it not knowing how much it needed when I was at the pool store. Of course it was new also, but no sand in the pool.
I'm getting a new gasket, then we'll go from there.
Happy swimming!