Life of a Reef

it depends on how well you take care of your system. If you take care of it, you could theoredicly have it forever. however, some people believe that eventualy you will have to replace yoru deep sand bed because of all the toxins it coudl absorb. But im talking like a decade for that. and i havent seen any actual studies about it.
 
i dont see why it cant be eons with good care, i wouldnt say forever since all reefs will die out in the wild.
 
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