Hammer Coral in distress

[charmander]

So heres the story
The first picture is my hammer coral about 3 days ago
two nights ago I noticed all four polyps looking funny so I immediately did a water change and the next day, yesterday all four heads looked fine
and now this is how they look today.

I don't have test kits but I know my salinity is fine.

I a few theories, let me know if you think I could be right
When I did the water change there was a significant temperature differance and I accidently pumped some cold water near the two closed heads

also today I forgot to turn my lights on until much later than normal. could either of these things have done this.
Let me know what advise you have. I am preparing for a water change tomorrow.

 

[2quills]

Without knowing all of your parameters it's all just guess work. How long have you had it?

 

[charmander]

it has been a few weeks anyway maybe 5 weeks.

All four heads are happy today so we will see how they look tomorrow.
I think I will do another water change anyway

 

[2quills]

They will close up like that when the lights not on for sure. Probably a combination of the light being off all day and then the cold water.
Non the less though, I'd definitely recommend investing in the necessary test kits if you plan on long term success keeping calcifying corals.