Was going to stay out of this-- until seeing references to algae wafers.
Top ingredients on the list of a popular algae wafer:
Fish Meal, Wheat Flour, Wheat Germ Meal, Starch, Dried Seaweed Meal, Dried Bakery Product, Dehydrated Alfalfa Meal, Dehydrated Alfalfa Nutrient Concentrate, Brewer's Dried Yeast, Soybean Meal, Fish Oil, Krill Meal, Spirulina
--So you have to go 5 ingredients in to get to the first algae related ingredient, thirteen ingredients in to reach the second algae related product.
Here's another one:
Wheat Germ Meal, Feeding Oat Meal, Corn Starch, Dehulled Soybean Meal, Cellulose, Potato Protein, Dried Yeast, Wheat Gluten, Algae Meal.
--Nine cheapo ingredients in and you finally see the only algae related ingredient.
Draw your own conclusions as to how well a bunch of cheap starch and grain based ingredients or mystery ingredients like "starch" or "dried bakery product" actually improves fish color or health vs. higher quality foods.
In fact, for a lot of fish, among the blue enhancing ingredients are krill, shrimp, salmon, etc, due to the astaxanthin, or other carotenoid rich foods, like spirulina, if it's not thirteen ingredients down after a bunch of wheat, corn, soy, starch, and re-combobulated baked goods waste.
Algae rich foods are one thing, fish matzos with a pinch of algae thrown in is another. Good idea to check the ingredients, calling something an algae or veggie wafer doesn't always mean much.