New Welshies not getting calcium?

[Stoney Meadow Maple]

They are newcomers; the previous owners likely didn't provide oyster shells, so they have no clue what the white shells are for. Over time, as they get better acclimated to the flock, I bet they will see the other flock members eating the shells, and they will slowly learn.
Most calcium supplements are fairly soluble in water.
That would be another route to get the calcium inside them, if you lock them inside the coop, and provide a dish of water laced with calcium.
If they don't drink the water, I think they might actually be chickens.

They like water for sure, only reason I haven’t tried lacing water with calcium ... or feed , is because of my drake, i hear its bad, but exactly what does too much calcium do to them?

 

[Isaac 0]

They like water for sure, only reason I haven’t tried lacing water with calcium ... or feed , is because of my drake, i hear its bad, but exactly what does too much calcium do to them?

I should have explained more.
If you were to offer the calcium-laced dish, you would want to let everybody out of the pen, besides the WH, and wait for them to drink the whole dish.
Tedious I know, but your options are limited.
Males have lower calcium requirements than females as they do not lay eggs; I do not think it would be something you would see in a few days, but over time, excess calcium can lead to renal and skeletal issues.