i have one blue gourami in a 10 gallon aquarium but soon im gonna put like 2 more fish in there and ive never had fish before so i have no idea on the water changing
crunching up the flakes is a good idea too.. often if you throw in large flakes they will nip the flake, and it will sink to the bottom... for 1 gourami i would probably crunch up food about 1/2 the size of a penny.. 1 fish wont eat that much