How to tell if a red macro algae is growing?

[Newms118]

This is a pretty simply question, how can you often tell whether a red macro is growing? I have some Bryothamnion where there tips were all fluorescent when I got it from live-plants.com. Slowly over a couple of days, the tips when from being really bright orange under my actinics, to more a faded fluorescent. And today I noticed that all the tips have turned a bit clear. Things is I cant tell if that is a sign of growth or death. Thats because other plants that I have are clearly growing, like a Rhipocephalus phoenix, codium, and some halimeda.

I tend to feed pretty heavy and my nitrates have been between 10 to 20 ppm. Calcium is 450 to 500 ppm and Alk is between 8 to 11 dKh. I've also added some Kent Marine Iron and Manganese Plant Supplement and the Iodine supplement as well. Aside from lighting and flow, I'm not sure what else to adjust.

 

[Michael Hoaster]

I'm pretty sure the color change means it's dying back. If you have plenty of nutrients, try moving it into slightly dimmer light. None of us can grow everything. We try a lot and some survives.

 

[Diana A]

Bryothamnion does not like very bright light. It is used in DT at the base of the rock

 

[Newms118]

Bryothamnion does not like very bright light. It is used in DT at the base of the rock

I essentially have three bushes of this stuff, one is in the middle of the tank, the other is toward the bottom, and the last is in the fuge. None seems to be the best spot since they all seem to be experiencing the white tip issue. I guess I can just take some and put it at the very bottom and see how that works out. Or maybe put some in the shade, sort of under a rock so that its not getting direct sunlight.