My ammonia levels seem to be around .5ppm in my tank. I am not sure why it is not 0, my nitrates and nitrites are exactly 0ppm.
What can be causing my ammonia to be so high, and how can I lower it?

I recently did add some live sand in my new sump,
some calupera algae, 3 sea anemones and 2 clown fish in the display

The calupera algae looks a little diff then I would think. There is usually small green vines with bubbles on them, now it seems that some of those bubbles opened to flat pancakes and it looks like a small tint of brown in spots.

Water parameters are perf except the .5ppm ammonia level.

Any ideas?