Isa Browns and Rhode Island reds together

[Sandstock]

I have three Rhode Island Red hens in with Rhode Island Red rooster and 7 isa brown hens and one white hen. All great layers and I have been selling fertile eggs and incubating myself as well. Just wondering how I can tell the eggs apart so I can offer pure reds as opposed to a mix. Also how can I tell the pure red chicks from the cross breds

 

[aart]

Simplest would be to put the RIR hens in a separate enclosure with nests and only hatch eggs from those nests.
That might also allow you to learn to ID the RIR eggs without separation in the future.

I have a temporary partition wall I can install in my coop, has a separate run too.
It worked great a few weeks ago when I was trying to pin point who was laying a certain colored egg...
.....only took a couple days to suss it out.

Have you been able to tell the difference in the chicks as they hatch?
I have no clue if those chicks would look different enough to tell, just a thought.