i respectfully disagree with that guy. i know for a fact that macros will entirely wipe a system free of nitrates and phosphates, hence my system that is completely macros. i struggle to keep nitrates above 3pmm and phosphates are always untracable. i even add fertilizer to that tank...

now, i have never grown chaeto, maybe it isnt that great for nutrient uptake, after all it does have a small biomass. but macros like caulerpa, graciliaria and halymenia, are excellent at nutrient uptake and are all edible for herbivores. and just because you have a refugium doesn't mean you should stop doing water changes, that one grumpy guy kinda made it sound like the only possible way to remove nutrients was to siphon water and thats it there is no other way period, just dont even try, lol.

---------- Post added at 11:27 AM ---------- Previous post was at 11:26 AM ----------

oh and if youre having trouble keeping a macro in a refugium that is on a reef tank, its almost always low iron. they have ferts for that.