Welcome to tfp

Which kit do u have? Be sure to add it to your signature.
How did u get cya of 57?
If it looks anywhere in between 50 & 60 on the Taylor cya test you round up to the next “10” & call it 60. Chlorinate accordingly
FC/CYA Levels .
Be sure to toggle on csi tracking in poolmath so u can take care of your pool surface properly.
How is CSI calculated? Very simple – use our PoolMath tool. To ensure long plaster life and save money, click here to learn more.
www.google.com
How are u currently chlorinating?
Your ch is a little high.
Liquid chlorine or a swg is your best bet as they don’t add unwanted cya or calcium which build up & require water replacement to lower.
Before chlorinating your pool, you should know these simple tips. Learn the best way to add chlorine to your pool.
www.google.com
As far as the sparkle goes

some like to add a little D.E. To their sand filter to “polish” the water & help filter what’s too fine for the sand alone to catch.
Here’s the how to
A clean pool filter will increase the efficiency of your pool! ... your filter are to backwash it, clean the manifolds and grids, and add new DE.
www.troublefreepool.com
Your dolphin, with its fine filter cartridges, will also be like a little roving xtra filter.
If u are ever in doubt about the clarity you can always do an
Overnight Chlorine Loss Test to rule out the presence of organics. That’s the beauty of being in control and testing your own water - you can catch little problems BEFORE they become big ones

Congrats on taking charge!