Squeeze out some balls of Growpito for your seedlings that have already been pre moistened then mist them a bit. No need for rapid rooters. I use a Grodan starter plug tray that I press Growpito into and can be used for seeds or clones.
By allowing them to wait 5 days until your first flood it will allow the medium to dry a bit and subsequently pull in oxygen.
I'm probably worrying about nothing.
Sprouts happened 3 days ago in Rapid Rooters.
1 day ago I put the RRs with sprouts into 2.2 Gal conditioned Growpito (250 ppm) under about 10,000 Lux of light.
I also wet the planted RRs with distilled to allow the fertilizer from the Growpito to slowly seep in.
So far so good, and if this method comes close to hydro in quality and yield, I'll be a convert.