I know it's got something to do with that pool of water but do you pour the potion in there or does the pool somehow allow you to create a potion?

If not, how do you create a glade potion?

First, you need to buy an Ornate Floral Pitcher. Get this from either the user shops, trades, or wait until it restocks in the token shop. Take this to Peka Glade and you can fill it up. However, the Glade is only open at certain times during the day. I think it's 8:00AM and 8:00PM. After filling it with water, it'll turn into a Glade Potion. You can also buy them in the user shops at around 20 mil.

Thank you for the information.