Did the parvulus use the flower pot ?
I used one in one tank, and this is the one in which the fry did not stay after becoming freeswimming, I think it was too open. They still survived though, just didnt stay the normal period in the cave.
What about the air filter – have you made certain that no fry is going to be ‘sucked’ into it ?
I like your setup, I think its fine.