If you keep them in a small water volume, it's better to change the water from time, to time (every other day is enough).
If they are in a bigger volume (around 1 liter) with lots of plants, no need to change the water so often.
If you have only 5 eggs, the emergency will be to separate the presumably good eggs from the other since bad eggs end up molding and this fungus could reach the good eggs.