It's not just the reef side... it's the aquarium hobby as a whole. Lighting I can understand. You can't get the same lighting off the shelf. Filters, skimmers, stuff like that I agree. Also substrate. In the fw
world, a lot of us use pool filter sand. It's just plain old silica sand. If you get silica sand with the word 'aquarium' on it, the price is raised at least triple.
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