Use the fish in the move in bounded box,when you first start set the speed to a low number so the fish won't run away so fast.then play with the numbers to get them the way you want them.

Here is the animation scripts for them

FISH TANK ANIMATIONS

It looks like this an example (fishtank_fish16_ani) put that in the state box then press enter

Angel Fish Big.........................fishtank_fish16_ani
Angel Fish_01.........................angel_fish1_ani
Angel Fish_02.........................fishtank_fish14_ani
Angel Fish_06.........................fishtank_fish24_ani
Angel Fish_Lagoon.................lagoon_fish01_ani
Angel Fish02...........................fishtank_fish2_ani
Angel Fish03...........................fishtank_fish3_ani
Angel Fish05...........................fishtank_fish1_ani
Aquaplant01............................fishtank_plant1_ani
Aquaplant02............................fishtank_plant2_ani
Aquaplant03............................fishtank_plant3_ani
Aquaplant04............................fishtank_plant4_ani
Aquaplant05............................fishtank_plant5_ani
Aquaplant06............................fishtank_plant6_ani
Aquaplant07............................fishtank_plant7_ani
Aquaplant08............................fishtank_plant8_ani
Aquaplant09............................fishtank_plant9_ani
Aquaplant10............................fishtank_plant10_ani
Aquaplant11............................fishtank_plant11_ani
Aquaplant12............................fishtank_plant12_ani
Aquaplant13............................fishtank_plant13_ani
Aquaplant14............................fishtank_plant14_ani
Aquaplant15............................fishtank_plant15_ani
Aquaplant16............................fishtank_plant16_ani
Aquaplant17............................fishtank_plant17_ani
Aquaplant18............................fishtank_plant18_ani
Aquaplant19............................fishtank_plant19_ani
Blue Fish.................................blue_fish_ani
Butterfly...................................butterfly_ani
Carousel Horse.......................carousel_horse_ani
Clown Fish..............................fishtank_fish4_ani
Clown Fish_01........................fishtank_fish15_ani
Clown Fish_02........................fishtank_fish10_ani
Clown Fish_Lagoon................lagoon_fish02_ani
Colbert Report........................colbertreport_ani
Crystal Palace ........................crystalpalace_ani
Danios_01...............................fishtank_fish25_ani
Danios_02...............................fishtank_fish26_ani
Danios_03...............................fishtank_fish23_ani
Danios_04...............................fishtank_fish20_ani
Danios_05...............................fishtank_fish18_ani
Danios_06...............................fishtank_fish13_ani
Danios_Lagoon.......................lagoon_fish03_ani
Danios07.................................fishtank_fish5_ani
Diving board............................divingboard_ani
Ferris Wheel............................ferris_wheel_ani
Flag..........................................flag_ani
Helicopter.................................helicopter_ani
Intruder.....................................intruder_ani
Jellyfish.....................................jellyfish_ani
Kelp..........................................kelp_ani
Lovingchair...............................lovingchair_ani
Manta Ray................................manta_ray_ani
Octopus...................................octopus_ani
octopus_ani0
octopus_idle0
octopus_idle1
octopus_idle2
Oscar_01.................................fishtank_fish19_ani
Oscar_02.................................fishtank_fish11_ani
Oscar_Lagoon.........................lagoon_fish05_ani
Reef Fish.................................reef_fish_ani
Rinabo_01...............................fishtank_fish17_ani
Rinabo_02...............................fishtank_fish12_ani
Rinabo_03...............................fishtank_fish9_ani
Rinabo_04...............................fishtank_fish8_ani
Rinabo_Lagoon.......................lagoon_fish04_ani
Rocket.....................................rocket_ani
Rotating Doors........................rotatingdoors_ani
School_Lagoon.......................lagoon_school03_ani
Sea Dragon.............................sea_horse_ani
Sea Turtle................................sea_turtle_ani
Shark.......................................shark_ani
Star..........................................star_ani
Yellow Fish_01.........................fishtank_fish21_ani
Yellow Fish_04.........................fishtank_fish22_ani
Yellow Fish02...........................fishtank_fish6_ani
Yellow Fish03...........................fishtank_fish7_ani

Here is a tool that was made by Sifupeter it helps to set your fish correctly, maybe someone can show you how to use it the correct way.

Your virus protection may try to block you from downloading it, the tool is fine and virus free.




Some time back I wrote a small hta tool that does the calculation / objects for any size of aquarium with fish and plants.

It might help.

http://sifupetertools.com/Deco/Fish.hta

Notice that I am lazy by design. So almost all things can be clicked on to copy it into clipboard and then simply pasted in the editor.
It works by starting with a Fishtank Glass. Place it where you like and make it any size you like.

Whatever the numbers, fill those in the tool. It needs the scale, rotation and size to calculate the exact position for all the items. Notice the button: Use the above numbers in calculations. Make sure to click it after filling in the correct size as you used in your location.

There is a tab for general props. Just click and it will give the exact x,y,z etc. Just click, it will automatic copy to clipboard. Paste it in the editor. Same with Plants. It does include the animation state and hints as to what you need to change

Fish too comes with the correct animation. Just click at each property and paste it in the editor

Some fish do not have animation, they hail from later additions to props. So they can be added in the fishtank by using the Move Within Bound Box script. Notice that MWBB must be done in correct order, otherwise your fish moves outside your fish tank before you are finished with settings

Enjoy