The short & simple answer is no, it's not a good idea to feed foods designed for dogs, to fish.
Here's a comment I made in the past on this subject ................
There is now over 100 years of research that has taken place in the aquaculture circles involving both commercial cold water, and warm water ornamental species of fish. While the species specific data may be missing for most of the ornamental species kept in the hobby, in most cases one can extrapolate the data from what is available regarding warm water carnivores in general, warm water omnivores in general, and warm water herbivores in general, and in general apply that science to all species of warm water fin fish that fall under each designation. One can also study what nutrients the fish consume in the wild, and what levels, and also use that data to formulate a general feed designed for most ornamental species. The basic requirements are all very similar, for the most part the nutrient levels are the only thing that changes, as in % of protein, fat, carbs, fiber, etc.
Dog food is formulated for dogs.
Tropical fish are not hard wired to consume large quantities of animal fat or protein derived from beef, chicken, and god only knows what other animal sources some manufacturers may use. Dogs in general have certain dietary requirements, including various levels of vitamins & minerals, which can even vary due to age (puppy/adult), the size of the breed (Chihuahua vs Great Dane), and/or working dog vs lap dog, and these are NOT the same basic requirements required by most species of fish.
This is not to say that one cannot feed dog food to their fish, or that doing so is going to cause immediate death in their fish, in general it won't, but that doesn't mean that this is a good practice that is in any way based on any type of sound science or research, because it isn't.
If you want to feed a lower cost food to your fish there are plenty of commercial farm feeds that are designed for fish, and that are far less costly than some of the premium brands of food on the market. There is simply no need for anyone to be feeding dog food to their fish. It makes absolutely no sense from an economic view point, or nutrient wise.
It's just a dumb idea, period.
More info in this following past discussion regarding marine species.
http://www.monsterfishkeepers.com/f...aste-of-The-Wild-Salmon-Dog-food-as-fish-food
Again, If you want to feed a lower cost food to your fish there are plenty of commercial farm feeds that are designed for fish, and that are far less costly than some of the premium brands of food on the market. IMHO the pond food being discussed in this thread is certainly NOT something that I would consider feeding to a predatory species, in fact, I wouldn't feed it to anything. There are much higher quality bulk foods out there offered by various commercial feed mills.