It is day 18! But before "lockdown" starts you might want to check those chicks one more time. A lot of people do a final "candling" but at this point you cant see nothing but the air sac most of the time so seeing movement is a challenge...what's next.."water/floating test"..now let me tell you what I know about that from my own experience..Floating does not matter! I have seen articles and video of others doing this and as soon as an egg sinks they maybe wait 2 secs before saying it's no good..or as soon as it sink they automatically say it's no good.. well...today's gonna be turning day 19 for eggs. On day 18 I did the processes stated above. I had two sink the rest floated but all of them moved..yes even the sunken ones. My rule of thumb is to wait no less the 10 sec without movement before tossing them out. Why?? The two that sank were obviously larger, thicker and when candling the chick seemed bigger than the others..weight and size to effect buoyancy (floating)