If you really want a book that tells you about filters, water chemistry, diseases and common plants and fishes, then look for Baensch Aquarium Atlas freshwater fishes, volume one. It is a very informative book, although expensive so check out secondhand bookshops for them. There are 7 volumes, and some saltwater ones too. The other volumes are more unusual fishes and plants. The book comes in hard and soft cover. The hard cover is more expensive than the soft cover but the information inside is exactly the same.
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