Yes, the nutritional value of lettuce it typically low. Iceburg lettuce has no nutritional value. However, you can use other varieties that are nutritious. For example, organic cimarron red lettuce. I get it in the organic section of the produce department. I also get my tangs to eat organic chard, organic kale, and organic dandelion. I just peel the leafy parts of the plant away from the veins and midrib. Then I soak the leaf in RO, selcon, mysis, krill, brine, squid, cyclops, garlic, and spirulina. I rubberband a piece to a rock and drop it on the sand bed. My tangs and Hoeven's wrasse tear it up. I also use red and purple sea veggies and Nori from the super market. It really seems like all my tangs like the variety and my inverts like the serpent crab, hermits, and snails also eat it.