Hey Magda, these are lovely photoshop pieces. :) I do like the idea of the fish tank, I can see the florescents of the lighting in the tank really creating some atmosphere but maybe you could experiment with the setting the tank sits in. A tank in a living room is quite normal and even though you have added elements you think are uncanny the setting may just counter act them. I could be completely wrong and it could work brilliantly but what about placing the tank in a setting that is not common to find one. In the middle of a forest, a train platform, a stage...and so on.