You can nori at Whole Foods or other natural grocers for less than "aquarium ready" nori. For example, you can get 10 sheets (> 9 oz.) of premium nori at WFs for $4.99. Cut each sheet into 3 pieces and you have 20 strip and a half meals (I have a 125 with many herbivores) for each meal for $0.25. If you use need a lot of nori, they have 50 sheet bags as well. I can't tell from Indo Pacifics add how much Nori you actually get- Two 1/4lb (4oz) + a 6" x 12" bag (how much is this???) for $50.00! The advantage I see might be in propagating your own nori, but this seems very expensive.