Try and keep your chlorine between 3-6. In a pool with 17,500 gallons, each 3 quart jug of 6% bleach will raise your cl by about 2.5 ppm. Test your water each evening and add enough bleach to get back to 5 or 6.

I would go ahead and wait a few more days before deciding whether or not to add a bit more cya. You can run it at 30 ppm. Many people do and do just fine with it at that level. I would suggest trying that first and then if you find that you are not able to keep a chlorine reading through a hot sunny day, you can always bump it up a bit to around 40.