Your YouTube indicates that you used Alden Leeds product, "Conquest". According to various MSDS sheets, this has been, and still is, a product containing 60% HEDP. Since this is the normal production strength of HEDP, that's probably all that Conquest contains.

If you overdose with HEDP in waters with relatively high calcium levels, you can precipitate a calcium phosphonate colloid. But (a) this is uncommon, and (b) normally it won't settle, but will leave your pool cloudy forever. There may be some unique mixture of conditions in your pool that caused the calcium phosphonate to settle -- lucky you -- if that's actually what happened.

Bottom line: overdosing with HEDP is NOT a good idea. This is definitely not a product where, if a little is good, more is better.