They're both designed to do two different functions,... Carbon is usually used to remove any toxins in your water ,to clarify the water and also to eliminate any odors associated with the water itself,..some reefers do not use carbon on a regular basis but I personally run it in a reactor all the time.
is used to remove and at least control the phosphates from your tank ,it helps to control algae outbreaks by eliminating the " food" they need to use to propagate,... I think you'll find a need to run both thru a reactor IMO
Brs has a high capacity gfo
that I've found works nicely but it's also rather pricey.
I hope this helps alittle
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