Fish represent an spiritual aspect of your emotional nature and also represent particular spiritual concepts. The dream would suggest that you are having a problem with this aspect of yourself. Aquariums represent a man-made spiritual environment. The fish getting out of the aquarium, reflect the idea that when you use the spiritual concepts you find in such man-made spiritual environment, your spiritual feelings put you into the position of being "a fish out of water", that is, you end up not being in a spiritual environment at all. (Note that water is the main symbol of The Spirit.) You appear to be having a difficult time in "picking up on" this fact.

In your mind you have, or could resurrect a spiritual concept encountered when much younger.
The spiritual environment in which this concept is seen does not look all that good (tank is cracked and dirty) to you. The tail/tale that belongs to this concept could be seen as having been "cut short". The spiritual approval for this concept (the blue colour) does not have the same emotional appeal as it once did. (no longer a vibrant blue) But, it seems certain to recover its former status.

In general dreams with fish can be seen as suggesting that "something fishy" is going on. Something is not quite as it should be.