Dealing with the Water Pincers is the easier of the two quests, both in terms of finding it and in terms of completing it- the Water Pincers are easily visible, extremely large insectoid creatures that skate around atop the water of the pools.  For all that there are a lot of them, they’re relatively fragile and easy to kill off.  It’s no real trial to wander until you locate a pool that has a bunch of them in it and just knock off six of them.

More challenging is the Sun Pearl.  If you look carefully to the Southeast of Liang’s hut, you can find a small gazebo next to an especially deep pool with several Barbed Ray creatures in it.  At the center of the bottom of this pool is an ancient clam, which holds the pearl you need.  However, in order to get to that clam and its prize, you’re going to need to get past several rays, which are aggressive.  This isn’t all that hard either- but then you need to face Fang-she, a surprisingly large water serpent that guards the clam.  If you’re unprepared, this creature can deal a fair amount of damage to you, despite being an ordinary level 6 beast.  Fortunately, a little caution goes a long way- as long as you know it’s there and don’t take much of a beating before starting your own hits, Fang-she should go down pretty quickly.  After that, it’s just a matter of swimming down and using the clam to open it and get the pearl you need.

With that done, you can actually just return to the gazebo at the edge of that pool- Liang has followed you down here, apparently to meet with Aysa Cloudsinger.  He thanks you for thinning out the Water Pincers, and your bringing him the pearl prompts him to mention that he doubts Shu really understood why Liang didn’t come back to the pools to play anymore.  Liang also explains that mostly Shu just didn’t want to be alone and unwanted- the spirit wants to be needed and to spend time with people.  Earning his trust isn’t hard- he wants only company.

Liang also gives you a new shirt or top, a nice step up from your current garb.

This moves you on to the next quest- Shu the Spirit of Water.  The spirit in question is sulking in the pool immediately North of the gazebo.  Liang instructs you to cross the rocks there and then drap the pearl into the center of the pool- Shu will apparently know what that means, and then you can coax him into playing a game.

The first thing you need to do here is head straight to the North.  There are several swirling circles on the rocks in this pool- clamber up into the one on the lowest rock and you will be launched from rock to rock until you are next to a higher pool, one that you could not reach before.  This is the Pool of Reflection, which is composed of water that, for whatever reason, you can walk on.  Step out to the middle of it and then use the Sun Pearl from your inventory.  Shu will rise from out of the water, and perch on one of the rocks in the Pool of Reflection- the quest will show up at the top of your Quest Tracker for completion- apparently Shu likes you.  This starts the quest ‘A New Friend’- you are to walk into five of Shu’s water spouts, which you can manage thanks to the Water Walk effect that lets you stand on the Pool of Reflection.