I suggest that you clone something with how many Korean games handle revives: if the player is below a certain number, then give that player a few free revives.
For Spiral Knights, 3 is a good number. If the player has below 3 sparks at midnight, set the player's Spark count to be 3.
If you do not agree, here is my reasoning.
I agree with this entirely, actually. I haven't run into problems with sparks, but it seems way too common for players to do so. Some method of rewarding sparks akin to this would really benefit those players.