Answered by Shaykh Faraz Rabbani
Is it good to keep an aquarium at home? What I heard is, it is not of baraka to keep fish as a pet. Is this correct? Can you please explain this?

Walaikum assalam wa rahmatullah,
I pray that this finds you well, and in the best of health and spirits. May Allah grant you all good and success in this life and the next.
In terms of permissibility, it is permitted to keep pets if one is sure that one will take proper and dignified care of them. The same thing would apply to keeping fish in an acquarium. If there is any fear, however, that proper care would not be taken, then it would be best not to keep a pet or acquarium. [ Nahlawi, al-Durar al-Mubaha]
And Allah alone gives success.
Faraz Rabbani