(Player group((Owner of Aquaform_Caster[TempInt])))
That's the only leak I could find.
A simple solution would be to store it in a Force (player group) variable, display the text message, then remove it using the function DestroyForce.
By the way, instead of setting the special effects in the cast trigger, you should have a trigger for user configuration that runs on map initialization.
Another thing I recommend is storing values into variables so you don't have to repeat them.
In your cast trigger, you stored the (Triggering unit) into the TempUnit variable, but you used (Triggering unit) throughout the rest of it anyway. It's always better to use the variable.
Reading from a variable is much faster than re-getting the triggering unit.
You can also apply this concept for (Last created unit) wherever you're creating dummy units.