Chalice losing color

[nanoreef11]

Hey there, im new to this so i dont know if this gets any attention but i need help with my space invader chalice. I got it around a week ago and it came in beautifully bright green but over the week the middle started going really dark and i cant find anything about this anywhere. I changed its position like twice but i dont think its helping . Ill attach the before and after pictures

 

[Mr. Mojo Rising]

Can you advise the water parameters please, nitrate phosphate alkalinity calcium magnesium, how old is the tank, what type of lighting, and what flow in the tank? sorry for the all the questions but all the info is needed to help you, we don't know your tank so need your help to describe it to us, thanks.

 

[nanoreef11]

Can you advise the water parameters please, nitrate phosphate alkalinity calcium magnesium, how old is the tank, what type of lighting, and what flow in the tank? sorry for the all the questions but all the info is needed to help you, we don't know your tank so need your help to describe it to us, thanks.

i dont think its because of the water parameters, my other chalices look happy as can be but i tested 2 days ago and my calcium was around 440, mag 1300, phos: 0.02, nitrate around 30 and alkalinity around 10.5. My tank is 4 months old , 13 gallons, The flow is moderate? And i have a AI prime and im using the David saxby signature series schedule