If one is dreaming about a fish tank and it is in their bedroom, this could represent that they have desires to be noticed or to be in the spotlight. They may feel like no one notices them or pays attention to them. This could also represent that they need to pay more attention towards their own needs and values as opposed to others’ needs.
The container of water with the fish in it symbolizes that they are feeling stagnant such as being stuck in one place at work, school, home life, etc. This may also signify that there are many things in their life that are coming up against resistance and not going anywhere, either through lack of resources or obstacles getting in their way.
Another possible symbolism of dreaming about a fish tank is resentment for someone or some situation where someone feels imprisoned by both feelings of frustration and anger at not being able to move on from this situation.