coraline turning white

[Kevin McG]

I have been noticing over the past couple of weeks some of the coraline on the sides of my display tank has been turning white. Is this normal?

I haven't changed anything with my lights and all parameters were checked tonight and everything is right on.

 

[Liam]

added any new carbon or improved your water clarity at all Kevin?

 

[Kevin McG]

added any new carbon or improved your water clarity at all Kevin?

Changed my carbon about 2 weeks ago... I did double the amount I normally use by hanging 2 medium bags in the sump but even them I am sure it is less than what most people use. Would that cause the white coraline?

 

[Kiah]

Exposure to air can cause it. It happens in my tank when I do large water changes, but only in the areas that have been exposed.

 

[Mini4x]

My question is will it come back, or should I scrape it all off? I just moved my tank and all mine turned white, except the bottom 2" or so (least exposure to air I guess).