yeah i mean you can feed that to big fish it just isnt as beneficial for them since it isnt nearly as filling as bigger things like raw/peeled shrimp, earthworms, mealworms, crickets, etc. i also disagree with feeding frozen chunks as then only a few fish will get it (i also think it would mess with their internal chemistry since they would then have a sudden drop in body temp which is not good) so i scoop up a little tank water swish the cube around in it until its all broken up and then dump back into tank and watch the chaos ensue