How big are they? When my pair started to lay eggs at approximately 3.5" the same thing happened. When they reached 4.5" the eggs startred to hatch. My pair was breeding all the time when they had tankmates. After the tankmates ate the fry, usually after two weeks, they would breed again, within a day or two. This happened many times. They've been without tankmates now for two weeks and nothing. Hopefully a water change will do the trick. Good luck.