any sugguestions for adding some color

Hola friends.
I'm just getting my tank going again. 55 gallon tank, 175 mh 14k, 250 watts actinic bout 75 lbs LR.
My tank is pretty bare right now. Had a bad crash a few months ago, and lost lots of my nicer corals during the down time. I've got a brain thats about a year old and that's about the most colorful coral, lots of mushrooms many are also a year old and have turned brownish maroon, but still look strong and continue to propagate. My levels are good no Amn, nitrite, <5 nitrate, 420 calc. should i get a alk test kit i've never tested for alk.
First question, what is most likely turning my mushrooms brown over time?
Second, What are some good corals that i could get (innexpensive is good,) that would add some vivid color to my tank? Give me your opinions, and some corals you've had success with.
 
Top