Is it bad luck to have an aquarium in your house?

It is all in what you believe and what you accept to be true.

According to hindu mythology, keeping lives in captivity is a bad idea. I heard from one of my friend that in a story of hindu mythology, one person had to be in jail for 7 years just because he had a parrot in captivity for 7years.

Keeping a fish tank in home is to keep a life in captive.

This is on one side.

The fish tank has to be placed at proper location to really bring good luck, and has to be maintained regularly to have good clean water, air and sunlight and food. These are required for fish to be healthy.

When you see them happily moving around in water, the happiness stays with you too.