Torch not extending all of a sudden

[The Cat Burglar]

Pretty much as described in the title. Ive had this coral for about 18 months and up to now ive had no problems. Last week it just stopped extending. I have moved it in the photo attached so i could get a clearer picture. Aswell as this some of my neon green GSP have stopped opening, and i can see the mouth on my frogspawn which i normally couldnt.

I haven't changed flow or lighting in the tank. 2 weeks ago i added a red fromia star fish and it died, my problem is i didnt realise it was dead for 3 days as it was hidden behind some rock. I did a 25% water change after removing the decayed star fish. I had no ammonia spike as a result of the dead star fish.

My tank is a red sea reefer nano and i am running an AI Prime HD for lighting.

My parameters are;
SG - 1.025
Ammonia - 0ppm
Nitrite- 0ppm
Nitrate - 2ppm
Phosphate - 0ppm (i have been battling GHA for a couple of months but im starting to win the battle.....)
ALK - 9.3 dkh
CAL - 400ppm
PH - 8.2

No results for Mag as i dont have a test kit.

For filtration im using a bag of chemi pure in my sump after my filter sock, Rowaphos in my media reactor, Tunze 9001 skimmer, bag of micromec balls and have a small amount of micro algea in the sump.

I have attached some photos so if anyone has any advice or insight as to whats happening id greatly appreciate it.

Sent from my SM-G920F using Tapatalk

 

[Pond Boy]

I see lot's of cano or red algae I would dose some vinegar. Start slow increasing as the bacteria build and help the corals with nutrient up take...

 

[Pond Boy]

I see lot's of cano or red algae I would dose some vinegar. Start slow increasing as the bacteria build and help the corals with nutrient up take...

[red] I wold take that skimmer off line as well[red]