Empty pool

[ThePoolGuy]

Even with a cracked filter, how did your pool empty out? Your skimmer should have ran the pump dry and lost prime. In either case, you should start adding water back in anyway.

Ditto...

You really would need some kind of leak or have left the Multiport on Back wash / Waste by accident in order for the pool to drain completely. Although I've never drained a pool, that is my best guess on what it would take to do it, but it wouldn't be because of a filter issues...unless the multivalve had a leak.