Since my display is just three live rock pillars, I currently have a live rock section in my sump that is full or rock rubble. The live rock section measures 10"W x 20" L x 7" D. Right now it just has live rock rubble and a backup thermometer. Not sure how much biological filtration it adds to the system, but there a bunch of copepods and such that like it in there. I am thinking of adding chaetomorpha to that section to 1) stabilize my pH at night 2)take up some nutrients I have a 65K grow light that i can stick over that section Just wondering if I should add chaeto to the system. My NO3 has always been around 5ppm and my PO4 ranges from .07 to .16 without using GFO. Should I clear out a section of live rock from the middle so the chaeto can tumble right in the middle? or should I clear out half of the rock closest to the wall which the light will be on? Does it even need to tumble? Good idea or no? I can put it on my apex to run opposite of the display lights. is there any detriment to adding macroalgae if my tank is running fine as-is?