colt with white tips

[adunne]

hello all - was wondering if anyone could provide some input.. I have a colt that is about 13 inches tall. it has many branches and sprouts.. some of its tips are turning white.? Its place about 1/3rd the way up in the tank under PC lighting. It has great polyop extention. even the white polyops are extended. is it
getting to much light? should i move it down to the sand bed?

params are good and everything else is doing great. The only thin near it are some zoas.

any advice?