Crap...just lost a large post...
You don't really need an Asian store, although that will often make it less expensive.
DIY Fish Food
You can use any human grade seafood and dried unseasoned nori (seaweed). In fact I use organic wildcrafted seaweed from Kalifornia, but it is
VERY expensive. My main issue is that not only are the fish resistent to prepared foods, but most of those foods have toxic substances in them.
I am not going to get into naming brands, or even those ingredients because I do not want to get into trouble with RC or even the manufacturers themselves (it has happened in the past), but they all have
justifications as to why they use these ingredients.
I don't buy it one bit because there are a myriad of ingredients not known to be harmful to fish that could serve the same purpose. In fact, the more paranoid part of my psyche leads me to wonder if in fact it isn't on purpose to generate fish sales.
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You can easily look up the ingredients in your favorite fish foods to find the offending substances.
I also don't like prepared fish foods because of the extraordinary amount of pollutants they bring with them like phosphate, nitrate, etc. Take some, soak it in RO/DI and allow to settle out. Then test the water. And I hope you have a change of pants. It is UNREAL how much pollutants we add just with our fish food.