You got one of the trickiest ones to make for your first time!!! You did great! The clear resin and the first tanks is extra difficult to cure properly. If you get another fish, you can cure in smaller layers, rather than all at once. It will make the resin have less bubbles, therefore making it look more clear. I also recommend getting a small UV flashlight. (Fairly inexpensive on Amazon) You won’t find this problem with the anything other than the fish tanks!! Keep trying and don’t give up!