Seeking advice growing out Tilapia tholloni

[Nebraska_cichlids]

I'd like to improve my success rate with T. tholloni. Here's the problem. I'm doing pretty well getting my pairs to spawn. I tried to leave eggs and fry with parents, but that doesn't work all that well. The parents are not defending the fry well enough against the other tholloni in the 75G tank, and the numbers are dwindling rapidly. I tried pulling the eggs plus egg tumbler. I get plenty of wigglers (but also substantial losses) and typically transfer the wigglers into a small container inside the breeding tank. The contained allows for free exchange of water but the pores in the container are small enough to keep the fry inside. The number of dead wigglers increases by the day and I end up with only small groups of survivors per spawn. The wigglers are tiny and I've tried any food I could think of, including Hikari First Bites and tank water injected and incubated with a few crushed flakes.

Any suggestions? Leaving the wigglers in the umbler a little longer? Aerating the small container in the parents' tank? Different food? Starting feeding later? Setting up an extra tank won't work; the basement is full.