by Gary Sutcliffe, WAKO
At one end of the fish food spectrum you have flake foods. At the other end are live foods and close cousins, frozen foods like brine shrimp or bloodworms. In between them is an alternative, paste foods.
I have been making paste foods for my fish for years. It is easy to make, much less expensive than purchased foods, and less work than most live food cultures. Since you keep them in the freezer you don't have the problems with live cultures going bad and the associated mess and smell.
There have been a number of paste food recipes published over the years. You can adapt them as you see fit. The base ingredient for most paste foods is fish. I like to start with a small can of tuna and a small can of salmon. I used to buy the cat food versions. That has more bones and other unidentifiable fish components than the stuff for human consumption. I feel the extra ingredients provide additional nutrients. I am not aware of any killifish species that filet their food in the wild. Unfortunately the cat food producers have changed to adding other fillers to their tuna cat food to reduce costs, and the straight tuna is harder to find.
I usually add other ingredients, depending on what I have in the freezer or what is on sale at the grocery store. I nearly always add shrimp. Small bags of frozen cocktail shrimp (the real small ones) are relatively inexpensive. I will sometimes add crabmeat (not imitation) if the price is right. A recent trip to the grocery store produced small bags of mixed sea critters for about $2 each. They included shrimp, clams, oysters, and squid. My daughter was relieved to hear they were going to be in the next batch of fish food instead of for supper.
Vegetable matter can be added if you like. I sometimes add some peas or spinach. One interesting addition is garlic. Garlic is touted for human heath, so why not fish? There was a discussion of adding garlic to fish foods on the Internet a couple of years ago. It was supposedly good getting rid of internal parasites. I gave it a try once. I had a female A. elberti that was wasting away. She was the only one I had, and I really wanted to get some eggs from her. I fed her paste food with garlic and she recovered long enough to produce some good eggs. I can't say for sure the garlic was the reason, but it sounds plausible.
Italian and Korean foods have a lot of garlic in them. None of my killies are native to these regions, and they didn't relish the garlic flavoring very much, preferring the less spicy paste foods. I have heard of some fish keepers adding a couple of drops of anise oil to their paste foods for flavor. I have never tried that.
Avoid beef, pork and other types of meat from mammals. One exception is beef heart, a favorite of discus breeders. I have used that when available.
To make the paste, get out the blender or food processor. Add your ingredients and start it up. If it gets too lumpy you might need to add water, but use as little as possible. Let the blender run until it is a puree. You want fine particles. It should have a consistency of a very thick milk shake.
The next part is the real secret. If you take the paste at this point and freeze it, it will melt into a cloud of fine particles in the tank. The secret ingredient is non-flavored gelatin. Take a couple of packages of gelatin and dissolve in as little warm water as possible. Dump it into the blender for about 30 seconds to mix it in well. Now you have to work quickly!
Pour the mixture into small zip lock sandwich bags. You want to fill the bags so that when they are laid flat you will have a block about 1/4" thick. You need to work quickly or the mixture will harden in the blender. Place the bags flat in the freezer and you are all set.
To feed I usually slice off chucks with a razor blade and chop them up to the desired size while it is still frozen. For larger fish I slice off wafers about 1/8" wide and then slice them into strips, sort of like short fat worms. Smaller fish can pick away at larger pieces as well. Some people use a cheese grater to break the block up into smaller pieces.
Some fish need to be trained to eat paste foods at first. If some of the other fish in the tank eat paste foods, the others will usually get the idea pretty quickly. I brought home some darters from the collecting trip last summer. They would only eat live foods at first, and even rejected frozen brine shrimp. They started eating paste foods the second time I tried it, and now really dig into it.
I try to feed my fish twice a day. In the morning I am rushed for time, so most of the fish get flake food. In the evening I will feed more live and paste foods. Because of its low cost per ounce compared to commercially produced foods it is especially good for growing out fish. It is also good for conditioning for breeding, especially for the larger killies.
Paste food is a great middle ground food compared to expensive flakes or frozen brine shrimp and is less work per ounce compared to live food cultures. Oh, by the way, they make great snacks for the cat as well!