Corals are dying PLEASE help !

[mxsnow145]

My Goniopora, rasta leather, montipora and polyps are all going down hill and im not sure why... i have lost more then 1/2 my polyps. the tank has ben established for more then a year and all of them where doing fine 3 weeks ago.
i am using LED lights
pH 8.3
Ammonia 0
Nitrite 0
Nitrate 0
SG 1.026
temp 79
DKH 8
calcium 440
this is before


this is after

 

[flower]

Have you tested for phosphates? When is the last time you changed the filters on your RO unit? Could anything like a penny be dropped into the tank by a child?

 

[btldreef]

Have you always kept your dKH at that level?
Have you always had LEDs, or are they newly added?
Test magnesium and phosphate
All the corals you're listing really don't need extremely high lighting, and I've seen LEDs harm most of the corals you're picturing from cooking them with too much light. You may need to turn down your LEDs.

 

[mxsnow145]

yes i did test phosphates they are zero also i changed the filters on my RO unit 2days ago i also did a 30% water change added new carbon and added new miracle mud, and started feeding them coral frenzy
my DKH is 9 and i have always had LED's and i just ordered a mag test because my LFS doesnt sell them
however they do seem to be picking up