HI,
I put one of those Green Turtle sand boxes in the dog pen full of water and me and my cousin pulled a Tarp over one of the corners of the pen to make shade because in the dog pen there isnt much shade,i try to keep the pool under the shade,i keep their water dish uned the shade to,and on the porch where it is cool as well,this seems to work very well,and they love it.......
good luck
-Kayla