Artificial hatching of egg layer eggs

Has any one tried hatchingAfrican substrate spawner eggs without the parents? I have a pair of L. leulupi that laid eggs several times. They are very protective of the eggs but for some unknown reasons, the eggs either dissappeared after a few days, or only a small fraction actually hatched. Out of 50 to 60 eggs, for example, I might have 10 hatched ifry if I am lucky, sometimes none. There are no pleco or fish bold enough to challenge the guarding parents so there can't be outside predation. Can the parents eat the eggs despite their protective behavior? I just don't know how the eggs dissappear and want to know the success rate hatching the eggs without the parents.