Are cardinalfish suitable for the fish-invertebrate aquarium?
Yes, they will do no harm to invertebrates or algae.
Is it normal for cardinals to prefer the darker areas of the aquarium?
Yes. It is a good idea to provide a part of the tank which has more subdued lighting particularly for the cardinals.

I want to make up a shoal of cardinals, how many should I choose?
As a good general guide, choose one fish every 12in (30cm) of aquarium length. So, if you have a 36in (90cm) aquarium, three specimens will be ideal; likewise five would do very well in a 60in (150cm) tank. To prevent any initial disputes, choose the smallest juveniles available and introduce the whole shoal into the tank all at once.
Will cardinals breed in the aquarium?
Breeding is not common in captivity and, to date, very few fry have been raised to maturity.
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