Ive tried similar recipes with no ill effect to the water. Mammalian liver isnt far off from fish liver. Liver tissue is the same among all creatures it just comes down to minerals and vitamins. Cow may not be the best choice but it is acceptable. you can probably find better ingredients than oysters and v8 though. I add crayfish, mealworms and earthworms along with the other things. Personally, i feed all of these ingredients to my fish at some point or another so I think its perfectly healthy to create this meal and feed it as a staple
By all means, if you see nothing wrong with your recipe then go ahead and feed it. I'm just saying it's not the best thing out there.
I see nothing wrong at all with the listed ingredients. Seems like a healthy stable diet to me. Seems most pellets are almost all grains anyway, I would rather my fish have this.
Pellets need something to bind everything together into the pellet form, that being grains of different types. With the OP's recipe, it's gelatin. Fish do need carbohydrates of some sort and a healthy pellet diet will always trump any homemade recipe.