163 Kingdom of Crystal Seas

You'll start the quest in Hydropolis, specifically in Kardia Square. A researcher from Broadleaf needs your help to figure out why the water here is so pure, hoping to solve the pollution problem in Sequoia Valley. Your first task is to collect three water samples from around the area.

All three samples are located in the southeastern part of the city. Don't worry about finding them; there are big markers on your map, and you'll see blue sparkles at each spot. The one sample that might give you a little trouble is located at the base of the tower with the stairs.

Once you've gathered all three samples, return them to the researcher. He'll then ask you to grab one more sample, this time from a small island situated just east of Makronos.

When you arrive at the island via your airship, a short scene will play, and then you'll have to face a monster. This is a Level 69 Jolly Jelly. It's a standard monster, so just defeat it.

After the fight, you'll automatically collect the final water sample. Head back to the researcher with this sample to complete the quest.