Not in the fountain, but under it.
You need the Princess message that you find in the Maid's room (castle first floor left). Take it to the girl on the second floor inside the Mill. You will get the Cosmic Symbols card. On the village fountain, press the three symbols and the Sun, and the secret passage opens. The kid with the pimply face will give you the key. It opens the hatch between the hay bales in the field.
You Go to the fountain and then you see the sparkle on the fountain on the right side of the fountain and then you walk to get it.
In the fountain
To get the green tube in Poptropica's Astro Knights Island, you need to visit the castle courtyard and find the robot seahorse in the fountain. Ride the seahorse up to the top of the fountain to retrieve the green tube.
There is one in the middle (upper part) of the spaceship fountain next to the Mordred Museum.
In the fountain. you have to find the password first.
In Poptropica's Astro-Knights Island, to find the Fountain Code, you need to retrieve the missing letter from Mordred's room. Once you get the missing letter, use it to decode the message and obtain the code for the fountain in the Knights' Chamber. Use the code to unlock the fountain and progress in the quest.
find it in the fountain. its glinting
Once you have built a new spaceship on Astro Knights Island, it will park on top of the castle whenever you leave the island.
you get in between the two stacks of hay but, you have to have the key. to find the key you go down into the fountain and you'll have to ask alot of questions to get it.
you have to find the UFO in astro knights island.
in main street you will find a fountain and walk where the shiny thing in the water is.
The coin is on the fountain in town square. Use it to enter the Museum and find the Library Slip. This will allow you to access the Dungeon from the royal library.