6qt rubbermaid, no holes/regular lid, 1:1 water/vermiculite, eggs go right on top of the vermiculite. Then they sit in my DIY incubator for 56 days

Just how I do it. Ive never messed around with light diffuser, I've never had a problem without it so I don't see why I would add complications of having to lock eggs into their positions.

Press N Seal may or may not do the same thing as the regular bin lid. My bins close snugly and don't allow much airflow in or out so I stuck with the lids.