Again replying to my own thread. Hope this information can help others.
The CYA in my pool caused the problem. For some reason over the winter the stabilizer went to zero . That had never happened before in all the years I have had the pool. I can't remember having to add stabilizer.
My primary sanitizer has been liquid chlorine . I use a chlorine feeder with 1" tablets ( trichlor) as a supplement . The stabilizer in the tablets kept the CYA in the water around 50 ppm . When I added the gallons of liquid chlorine at startup ,it did not last long without the stabilizer . As soon as I added cyanuric acid to raise the ppm to 30 ,the chlorine level held. I'm sure there are a lot of pool owners that know all this, I didn't. I hope this can help someone else, thanks for reading.