Corals not opening

[ravechild]

I have a hammer and an octocoral in my aquarium that don't seem to be opening as much as they used to. Any ideas on why this is?
My params are:
S.G - 1.025
pH - 8.0
kH - 180
Calcium - 320
Ammonia - 0
Nitrite - 0
Nitrate - Less than 5
Phosphate - 0
Temp - 80.1

 

[vyperone]

What about your lighting? How old are the bulbs?

 

[ravechild]

260watt PC lighting on a 55gal tank. Bulbs are roughly 3 months olds.

 

[jjboods]

kh and calcium are low. Not sure if that would cause them to not open as much, but they should be higher.

 

[ravechild]

Any ideas how to get those levels up and to keep them there??

 

[jjboods]

There are supplements you can use or you can use a calcium reactor. I hope you didn't add corals to your tank without researching and knowing that you need to add calcium for them?