I've read a bit about vegetarianism and vegan diets...or "lifestyles" as their proponents seem to enjoy describing them...mostly as a result of interesting lunchroom conversations with co-workers. There are a very few sources that claim this is an easy and straightforward route to health and happiness, but the vast majority of information includes warnings and provisos regarding the need for a cocktail of supplements to offset the insufficient supply of many vitamins and nutrients.
S
Savethemall
, you stated that "This is not a black and white thing. There are tons of ways to recieve nutrients.. tons of resources, and tons of options" and also that you would only consider forcing this regimen on your pets if you could find evidence that it wouldn't harm them.
Maybe there are "tons" of ways to obtain nutrition...but there is only one natural way, and that is to eat a healthy diet that contains what is needed, i.e. a "balanced" diet. IMHO, that is indeed black-and-white. If you need to add a handful of pills and supplements to a diet because the body needs them and does not derive them from that diet...then that's a lousy diet. A proper balanced diet requires no supplementation.
There is one animal species that has its dietary needs more thoroughly studied and understood than any other: Homo sapiens. It may indeed be fairly easy to answer those needs by supplementation, but a vegan diet without those additives is unhealthy...it's a statement, a moral stance, a line drawn in the ethical sand, an invitation to "look at how enlightened I am!"...but it's not a balanced healthy diet for Homo sapiens. You allude in your comments to how harmful the production of food is to the environment, how you want to sidestep that by finding an alternative balanced diet. It won't work; there are balanced diets...and there are alternatives that include supplements...they are mutually exclusive. If a diet requires supplementation, then it is, by definition, not a balanced diet.
In comparison to human dietary needs, the needs of aquarium fish are a black hole of mystery. Quality commercial foods draw on the information that is available and use formulations that answer the need. They include animal protein because that's the surest way to be sure the diet is complete, and it is likely also the most economical. The cans of fish food do not have a moral philosophy attached to them; they are intended to nourish the fish, and that's it. When the fish eat...they aren't navel-gazing or attempting to achieve some moral high ground; they are simply eating.
When you attempt to force your moral stance on the nutrition of these animals, you are being disingenuous. If you really worried about their welfare, you would feed them what evolution has created them to eat. If you are unwilling to do so, then frankly euthanization would be more humane than experimenting on them and thinking you are doing good.
I do want to clarify that my comment regarding your grammar and English was not meant in any way as a slight. I was responding to the bot question raised by
esoxlucius
and nothing more. I respect anyone who can communicate in multiple languages.