Coral not happy:(

[couture99]

Hi guys not sure what is going on with my tank... Water parameters are good
Ammonia 0
Nitrite 0
Ph8.0
Nitrate 10

Been doing pwc daily as these guys who have been thriving for yrs all of a sudden have shrunken up, and my lg one is getting what almost looks like rust...
Any ideas

The 1st three pics are from today... Will attach one from last week for comparison reasons

 

[couture99]

Last wk

 

[couture99]

Fish, inverts, and mushrooms and pesky Aptasia are thriving...

 

[Gti_Leo]

when was the last time you changed the light bulbs? maybe its not gettign the light it needs