Do brain corals change color?

[ntswift]

I've had my brain for about 3 months now. I moved it around in my tank when I first got it because I had a hammer coral in that I was trying to keep from stinging it. Anyway its been changing color darker and darker. It still puffs up and shoots out the white stuff like normal but the color just has me worried. If it was caused due to stress, will it change back? If not is there anything I can do to help it? TIA

 

[melosu58]

What are your water parameters?

 

[ntswift]

Thats a good question. I have to take it to go get tested this weekend because I dont have a good test kit. I know I need to invest in one but I just cant afford one right now. If I buy one I want to buy a good one and not a crappy one. What would I be looking for most that would cause this kind of change in coral? I know everything is important, but I'm just curious as to what levels are most important. I know my calcium is good because the last time I got it tested they couldnt read it because it was so high. Then again it could have been their test kit being bad. I use Oceanic salt and do a 10% water change weekly with DI water. I don't have a RO/DI unit yet but I have a DI that I got from a friend that hooks and unhooks from my tap pretty easily.