Well i have at least one more day before om happy down there. Then i have two tanks thats being siliconed together next weekend. One 250x80x70cm and one 244x110x60cm and ****loads of tanks to start up. I got a shipment of fish coming in three weeks.
I have explained why this is NOT a good idea, several times over the years. Cat food is NOT meant to be fed to fish, including this brand/formula of food. Honestly, if one can't figure out a way to keep a fish properly, they would probably be best rehoming them to someone who can. I get it, food isn't cheap, but it's part of the hobby.
So if you can't afford to feed a fish properly, then do what's right for the fish, don't be a dumb ass and feed cat food to it.
This is the guaranteed analysis from the cat food that was mentioned previously. A minimum crude fat content might be fine for Sturgeon, or some of the cold water species, such as trout etc - but NOT for warm water tropical fish, for the same reason that I stated to the OP.