If the parents are to be left with the eggs, it is best to provide as much peace and quiet for them as possible. You may want to set up their tank in your bedroom or a spare room where they will not be unnecessarily disturbed. Other than that, they should be treated as you normally do.
Some aquarists cover the tank with paper or black plastic and use peep holes to observe the fish. This can cause more disturbance than without the cover because there is no warning for the fish when the lid is going to be opened for feeding or for any other reason.
The best system for filtering a fry tank is a seeded corner sponge filter. Start your new Rotifer (roe' tu fur) bacteria colony by putting the new sponge filter with aeration into an established tank. This should be done long before you have to use it so that all you have to do is pop it into the fry tank when the time comes. The sponge will begin to discolor when you have the start of your colony.
The circulation of water is gentle, the fry won't be sucked into the sponge and even baby brine shrimp are safe with a sponge filter. Clean the sponge in a bucket of siphoned off aquarium water to protect the Rotifers from dying, wring it out a couple of times and it's ready to go back to work even in a completely bare aquarium.
Undergravel filters also work biologically, but are not as convenient to use in this instance. A scrupulously clean aquarium is essential for proper growth and health of your Angel fish fry, but with an undergravel filter, this is almost impossible to do. The water can look crystal clear while the space under the filter can be filthy with uneaten food and fish waste. This in turn causes ammonia build-up which is dangerous or even fatal to fish.
It is obviously very difficult if not impossible to keep a fry tank with an undergravel filter in it perfectly clean.
This is what I found!!