spawning Lamprologus brevis "kitumba"

A pair of my brevis have been acting like a spawning pair for a few months now, but I found their first surviving fry today all the way across the tank in another shell. Any suggestions to improve survival rates? The fry I found was already almost 1cm long. The other fish in the tank are: 11 rasboras, 1 baby synodontis, and 1 other adult brevis with a single blind eye who has trouble finding food, so she is unlikely to be very effective at catching fry. They are in a 20 gallon with about a dozen apple snail shells and some very small other shells. The shell belonging to the parents is far from the filter.

Thanks for the suggestions!

Wow you keep shell dweller with rasboras?? I assume they are in a hard water setup for them to breed? I should try this out myself..I would recommend leaving them in with the parents as they will protect the fry from the rasboras, synodontis and snails. The colony will slowly buildup with subsequent spawns.

The rasboras will tolerate fairly hard, alkaline water just fine (maybe not for them to spawn, but I just got them to keep the brevis feeling safe.) Much better than other dither fish I've tried. My brevis are quite happy to spawn! I think right now I have the water at pH 8.0 and KH of 200. It seems to be a happy medium, and fortunately is about what Frederick city tap water is. Maybe the brevis are just not good at breeding yet as a young pair. I doubt the synodontis is eating much fry as he's smaller than the brevis parents and they go after him very aggressively.

The little survivor is still doing well and growing!