Well, looks like it is time for a good shock. I thought I was staying on top of things, but missed a step or two. First, I did not ramp up the filter time on the pool as the weather and water warmed up. That mainly effected the clarity, but I also lost a lot of CYA over the winter. That I did not expect based on what I have read. Ended up having dull water and some algae present in the shallow end (mostly evident by dust when I brush). I added one lb of CYA a couple of weeks ago and it is now reading 35. I would like to get to 40 - 45 so will be adding more later.
I took apart the filter and gave it a proper cleaning this weekend and it was gummed up. Odd that it did not read higher pressure, but certainly was evident in the lower flow to the returns. I was getting 700 watts at 2500 RPM on the pump. There was a green tint to the top layer of DE. I did the overnight last night and lost 2. Currently shocking. The water looks great since I cleaned the filter and my flow is back (1000 watts at 2500 RPM). I also do not have any algae spots on the plaster so I am expecting this to be a short fight.
Thanks to Sam's for keeping bleach prices low!