I tried multiple ways this year with my eggs and they all seem to be working. All used 6qt tubs with press-n-seal and then lid snapped down.

1 - Eggs sitting in hatchrite
2 - Eggs sitting on diffuser sitting on hatchrite.
3 - Eggs sitting on diffuser with spacer with just water.

Currently sitting at 100% healthy hatched with all remaining eggs looking great.

I think I like #3 the best. Cheaper & cleaner. Just be careful of "sloshing" when moving them around. At day 55, just moved them to a 6qt with wet paper towels.