By far, the most common problem with keeping fish is overfeeding. Why is this so? There are a couple of likely explanations for why aquarium fish are overfed so regularly by their keepers. First, many hobbyist are not aware of the basic feeding guidelines. Second, fish tend to display behaviors that make us, the hobbyist, think that they are hungry and therefore need feeding. Third, hobbyists have a fascination watching fish eat, and what better way to get the fish moving around in the aquarium than to drop some tasty morsels into the water!
The reason of this article is to address the first reason for why hobbyists overfeed, lack of education. And hopefully the second and third reason for overfeeding will be curbed.
So why is it that fish always look hungry and scoot to the top of the aquarium when you approach? First and foremost, all fish are “opportunistic feeders.” In the wild, fish do not know when their next meal will come floating by, therefore, when they do have the opportunity to eat, they do just that, eat! When kept in a captive environment, fish do not loose those genetically engrained opportunistic feeding habits. That is, if there is food nearby they will eat. So by default, fish are always looking for an easy meal. This also means all fish are cannibalistic in nature. All fish will eat other fish if that fish shows signs of weakness. A weak or dead fish is simply an easy meal.
In the wild all fish have three objectives; reproducing, establishing and protecting a territory, and feeding. They have no time to read the paper, go golfing, or go shopping. So yes, fish will always look hungry. They have established a “learned behavior” of recognizing any time someone walks to the front of the aquarium they think they will be fed.
Overfeeding is a source of two major problems in this hobby. The first, uneaten food will sink to the bottom of the display or get trapped in the filter. If the food is not eaten and trapped in the aquarium it begins to decompose. At that point the aquarium will become polluted. Life cannot be sustained in a polluted environment. Basically this means death to all livestock within the confines of the display. The second problem is algae blooms. As the food “rots” it produces a tremendous amount of fertilizer. Fertilizer feeds algae (see Algae Guide).
Feeding fish is quite simple. Keep in mind that in nature fish eat constantly. You are better off feeding many small amounts of food to your display 20 times a day rather than overfeeding once a week. All food added to the display should be consumed within 30 seconds. Do not add so much food so that 3-5 minutes later it is seen floating around in the water. A key point to keep in mind is that with most fish, its stomach is relative to the size of its eye. It will not take much food to fill its stomach. However, most fish have a quick metabolism. Therefore, it is usually best to feed a very small amount several times a day.
Diet is also very important. Just imagine if you were fed a strict diet of nothing but peanut butter and jelly sandwiches over the course of your life. You would end up with several deficiencies, thus affecting your immune system and creating ideal circumstances for you to get sick. The same holds true for fish. If your fish are not getting a varied diet deficiencies may develop and your fish may get sick or worse yet their life span may be affected (see Disease Guide & Captive Life Span Guide).