I first heard about DIY fish food a few months ago (about 8 months into the hobby at the time), and when I started planning a planted tank I knew I wanted to give it a try. After all I have only natural plants and wood, why not food?
Total cost for the recipe is around $15 and makes a lot of food as you will see below. This is only 1/3rd of the original recipe I found – I can hardly imagine making the whole thing.
I started with 10 oz shelled shrimp and 10 oz peas. I food processed this until it started getting mushy.
I dissolved 2 one-a-day multivitamins in some warm water. This went in the food processor with the peas and shrimp.
I added about 1 teaspoon of Spirulina powder (Found at Whole Foods)
I continued food processing.
I mixed up 4 packets (total of 28 oz) Knox Unflavored Original Gelatin in 4 cups of boiling water, and stirred/squished until all the chunks were dissolved.
I slowly stirred in the food mixture.
I let it cool for an hour or so on the counter and then placed it in the refrigerator over night.
With an assistant (she puts up with me and the fish), we sliced it into the same size cubes that come in store-bought frozen fish food packs. Pictured is the 2nd of what ended up being 3 layers on a cookie sheet. This is a TON of food.
I froze these 3 layers overnight and then bagged everything – a couple dozen cubes per zip lock bag made 15+ bags.
To feed – I simply drop a cube in the tank right out of the freezer most days. The fish pick at it a few seconds and then chase it to the bottom when the filter current knocks it down. These cardinal tetras never ate off the bottom in the first year of having them and now they eat this right off the substrate with gusto. A whole cube is way too much food for them but I’m hoping the rest goes to shrimp and plants.
Some eating off the bottom; I took a video but it was pretty boring 
Maybe someone will get an idea that they hadn’t previously thought of from this. I could bring a bag to a future meeting if anyone wanted to try some.
Let me know what you think, and thanks for looking!