Do I turn on day 18?

[Scottishnewbie]

successfully hatched ducklings earlier this year and curently have some black rocks and some isa browns in the inci.....tomorrow is day 18...do i turn the eggs tomorrow or is today my last day?

and the humidity is at 77 - is this ok for chicks?
apart from that, is everything else the same as i would do for the ducklings?
thanks peeps - and yes i know you need photos!!!!!