Angelfish Care Tips:
Tank Size: For Angelfish tall aquariums with a capacity of at least 20 gallons are best suitable.
Water pH Level: The pH for an Angelfish tank should be maintained between 6.5 to 6.9.
Water Temperature: The ideal temperature for Angelfish is between 74 to 78 F (23 to 26 C)
Water Filtration: Water filters like the sponge filter and the hang on back filter are suitable for Angelfish. They are weak swimmers so a filter with a strong flow will affect their swimming peacefully.
Tank Setup: A 20 + gallon tank with a sponge or a hang on back filter with live or soft artificial plants with sufficient space for the Angelfish to swim around is advisable.
Food: Angelfish are omnivorous in nature and will eat shrimp, flakes, small pellets, meaty frozen foods etc.
Number of Fish: Angelfish can best be kept in pairs in smaller tanks and in a group of 5 or more in the larger tanks.
Tankmates: Angelfish are Cichlids and are very peaceful in nature. They can be kept with similar temperament fish. Avoid hyperactive fish like Tiger Barbs, Neon Tetras etc that are notorious fin nippers.
References:
https://www.petcha.com/how-to-choose-and-care-for-freshwater-angelfish/
http://www.tfhmagazine.com/details/articles/amazing-angelfish-full-article.htm
http://www.thatpetplace.com/freshwater-angelfish-care
http://small-pets.lovetoknow.com/fish/10-facts-about-angelfish
http://www.fishxperts.com/angelfish-tanks/
http://angelsplus.com/ArticleCare.htm