Goldfish usually react positively to having a light source, however it is unhealthy to leave your fish tank illuminated constantly and the light also encourages algae to grow rapidly. Eight to twelve hours a day is sufficient for a happy goldfish.
It would die.
it would just keep growing.
A nursery is a place where small plants and saplings are kept and grown for transplanting.
A bean seedling kept in dark develops chlorosis and its leaves become yellow.
Goldfish and angelfish have different temperature, water quality, and space requirements, making them incompatible tankmates. Goldfish are coldwater fish that produce a lot of waste, whereas angelfish are tropical fish that prefer warmer temperatures and cleaner water. Additionally, angelfish are known to be more aggressive and may nip at the fins of goldfish. It's best to keep them in separate tanks.