Acropora, should I cut off the tip?

[Exus]

This is a Kermit the frog acropora I got about 5 months ago. The tip hasn't been looking good for about 2 months now. It hasn't gotten worse, but it hasn't gotten better either. Should I cut off the bad looking areas or should I just let it continue the way it is? Its under about 400 par, so maybe it's getting too much light?

This tank is 8 months old and the other acropora and montipora digitata frags under similar par looks great.

My parameters are pretty steady at 5 no3, 0.04 po4, 8 alk, 420 calcium, 1500 mag.

 

[dadnjesse]

If it were me I would cut the top off, i'ts most likely dead where the Algae is growing. Good luck.