Trever, Correct - soaking food in medication can only work by accident, not by design. The medication should be dosed at mg per kg of fish mass per day. All the variables are uncontrolled: you don't know how much medication is in the food, you don't know what the fish weighs and you don't know how much it eats. I'm working on an article foor the forum, but it hasn't been posted yet. Here is the intro to it though:
Medicated foods
Oral medications are an excellent way to target internal diseases of fishes. Marine fish absorb aquarium water, so in certain cases, they “drink” enough medication from the water to effect a cure. However, freshwater fish actively export water from their tissues and do not take in aquarium water, so injectable or oral medications are really the only delivery system that works for them.
Years ago, there were a variety of commercially available medicated flake and pellet foods. Currently, there seems to be only one product on the market, so aquarists are faced with either forgoing medicated foods, or making their own.
Presently, many aquarists try to soak their fish food in medication and then feed that to their fish. The trouble is that this can never really work. Oral fish medications are always dosed on an “as fed basis”, usually milligrams of medication per kilogram of fish biomass. In the case of soaking food in medication; the amount of medication per gram of food is unknown, as is the weight of the fish, and so is the amount of food being fed. With that many variables, a proper dose simply cannot be formulated.
One drawback to oral medication is that the fish must be healthy enough to be feeding properly. A fish that is too sick to feed, may need to be either injected with medication, or tube-fed (see section elsewhere). In tube-feeding, since you have the fish in hand, it can be directly weighed in order to calculate an accurate dose.
The typical formula for medicated food is:
XX Milligrams of medication per Kilogram of fish mass in food, fed at 3% of the fish’s weight per day
- Select a medication and dose from the formulary below.
- Estimate the weight of all of the fish to be treated
- Prepare the medicated food – either gel diet, or dissolved with a solvent and sprayed on food
- Feed at a rate of 3% of the fish’s total body mass daily, or as indicated in the formulary
