Standard Deduction Vs. Itemizing. Adjusted gross income has nothing to do with itemizing, which is a common mistake may people make. The section on Form 1040A following Adjusted Gross Income is titled Tax and Credits and includes Line 40 for itemized deductions and Line 42 for exemptions.
Bettas being kept as pets will do well on a standard pellet food designed especially for bettas (I recommend HBH Betta Bites or Tetramin granules) with an occasional treat of frozen/live worms or freeze-dried brine shrimp andbloodworms. Pet bettas should not be overfed; a few pellets per feeding is sufficient.
If it's a fish that stays on  the bottom more get food that is tablets. Most fish eat fish  flakes. You can also buy granules if you want to get a Betta.  Sometimes, if you want to treat them, you can buy tube worms. They  love them!    Bettas eat baby shrimp or flakes but baby shrimp are  better.