Waving Hand Anthelia experts. How long can polyps grow?

[TWYOUNG]

I have a huge colony of WHA and it now has polyps at least 10" long. How long can they get and can they harm any other corals they come into contact with? It's getting close to my Polyp leather, Acans, Cabbage leather, gsp's(which it's already rubbing up against and if anything gsp is winning as some polyp tips look stiff and white-not a problem for me if WHA loses), and eventually torches which I figure can defend themselves.

 

[Troylee]

If it’s happy which it seems it is there’s no telling how big it can get lol.. as for stinging I believe your fine with the corals you mentioned.. running a bag of carbon wouldn’t hurt as there might be coral warfare.

 

[TWYOUNG]

If it’s happy which it seems it is there’s no telling how big it can get lol.. as for stinging I believe your fine with the corals you mentioned.. running a bag of carbon wouldn’t hurt as there might be coral warfare.

Yes I guess it's happy bc it grows like crazy. It does have one issue that somewhat concerns me. The tips of some of the polyps towards the back of the colony have turned whitish and seem stiff. The stalks of these polys move and look normal. Any idea what this could be?