Well, I finally found filter sand that works properly with the Intex sand filter grid. Thank goodness I won't have to go through this again for a few years (I have another 2 bags waiting to be picked up on my next trip over for future use).
Maybe there should be a sand thread started listing various brands that people find to work and not work in Intex sand filters which could be linked in the pinned
Useful links for fellow Intex Pool Owners thread. It would be worth it if it saved even a few people from the problems that I had, anyway.....
HTH brand pool filter sand in #20 silica works great, no sand ended up in the pool at all. I had ordered the Aqua Quartz sand online at Ace Hardware for ship-to-store pickup at my "local" Ace Hardware (100 miles round trip). The HTH sand was what they sent - I decided to give it a try, and it worked well. The HTH bags do not show a particle size for the sand.
In a pinch, Quikrete pool filter sand #1153 will work in the filter if this is all you can get, but it is too coarse to filter as well as a proper sand media given its minimum particle size equals the maximum allowed under the Intex sand specs and the max particle size is 4 times the Intex maximum size. However, it did keep the pool pretty (but not crystal) clear for the week we had it in the filter. It definitely had a fair amount of plant/leaf matter on top of the sand when I changed it out this morning, so I know it was working. However, it was letting a lot more dust particles into the pool when I vacuumed which the HTH sand now seems to be catching.
Southern Filter Media #20 silica (a possibly local brand sold exclusively by almost every local pool supply outfit I checked with in my area) will absolutely NOT work. Put this stuff in your filter, and you'll be seeing sand showers into your pool for the 3-5 minutes it takes to empty the entire sand content of the filter into the bottom of your pool.