Feeding Aquarium Fish 101

Feeding Tropical Fish; “A Hungry Fish is a Healthy Fish”

Feeding Tropical Fish is essential for good health, but over feeding, or feeding the wrong food type is the leading cause of death in aquariums.  The old adage “a hungry fish is a healthy fish” is true on several levels.

1. When a fish is healthy it is almost always looking for food.
2. As long as a fish is hungry and looking for food, they are most probably in good health.

1. A sick fish usually is not looking for food and, in fact in many cases, will not eat.
2. Over feeding will cause fowl water conditions, sick fish and the fish will not be hungry or happy.
3. Temperature not within the optimum range will cause sluggishness.
4. Most tropical aquarium fish can go for days without eating and still be hungry and healthy.

I want to review the basics of tropical fish feeding, and then get into some specifics on feeding and maintaining a healthy aquarium.

There are 2 main types of food to maintain a healthy happy aquarium fish – live and prepared.  The live foods are better for the fish, and what they eat in nature, but not practical for today’s average hobbyist aquariums.  Live foods are difficult to obtain, inconsistent in their availability and are not available in most areas on a year round basis. Aquarium fish can get along quite well on a mixture of live and prepared foods; in fact they can get along without any live food at all, and survive on only prepared food if that proves necessary.

In subsequent articles you will see that to breed fish successfully, live food is usually a necessity, but today’s prepared foods are fine for a tropical fish community aquarium.

Amount of Food Required:

The golden rule about feeding fish is simple: Do not overfeed: All the food given, including that which falls to the bottom of the aquarium should be completely eaten in about three minutes.  For example, twelve tropical fish of ordinary size (body measurement from 2/3 inch to 2+1/2 inches long) should be given enough prepared food to only cover the area of a US dime..  That is, about one quarter of one pinch – and that is enough.  The whole amount (including that at the bottom of the tank) must be eaten by the free swimming fish, catfish and invertebrates within the aquarium very quickly.  It is best practice to observe the fish still foraging for food long after the last flake is eaten for best results.

The frequency of feeding is a matter of some controversy, but once or twice a day should be sufficient.  If you are trying to force your fish to grow much larger quickly, you can feed up to 6 times a day at 3 hour intervals, but this is not recommended, it requires much more attention to filtration and water quality. Remember “A hungry fish is a healthy fish”.

Temperature enters into the feeding cycle as well.  Tropical fish kept in an aquarium temperature of 21C or about 70F or below, are sluggish and eat little; at 24C or about 75F they are ravenous; at 28C or about 82F and above, the lowered oxygen content of the water again robs the fish of their appetite.  The ideal temperature for healthy and hungry tropical aquarium fish is between 23C or about 73F and 26C or about 79F.

It has been proven and accepted that fish can go for long periods of time without any food whatsoever.  In nature there are points in time when a tropical fish whose natural environment may be in the Amazon, might be stranded in a mud puddle without food for days or weeks.  If you plan on being away for as much as a week, you can choose to make no special provisions for a long established community aquarium.  The microscopic life already present in the water of a well established aquarium will be sufficient for that period of time.

Leaving your aquarium unattended for up to a week is strongly recommended in preference to allowing an unskilled stranger to feed the fish.  A stranger to the hobby of fish keeping might be tempted to be mistakenly generous with the food, giving the fish all they want and more.  This can have unfortunate results; even kill your fish before your return.  Remember we discussed that ¼ pinch is about the amount for a small community aquarium, one full pinch a day is 4 times too much and a drastic over feeding, spread over a week this will foul the aquarium.

If a stranger must be trusted with the feeding, a good idea is to make up tiny packets with the food pre-measured, or buy one of those 7 day pill caddies and put your normal feeding amount in each compartment, this way the stranger will not have to rely on his own judgment for feeding amounts.

One method I like to use is to feed the fish live supplements to their regular feeding, during the 10 days before your trip.  This will help the fish store up surplus fat energy; the fish can then draw on this surplus in the absence of regular feedings, just like in nature.

Another method is to use special vacation blocks that dissolve slowly in water to release predetermined amounts of food each day.  These blocks are available in 3 day and 7 day versions. 

Finally there is a ‘jelly-type’ food that sticks to the side of the aquarium and dissolves very slowly, so that the fish can eat the food over a period of days, while you are away.

The most important thing to remember is; even though your fish will often beg for food when you walk in a room, this is their nature.  Just as with a dog, you must have set feeding routines, adjusted with time and growth. 

Buy high quality flake food, which is specifically labeled “does not cloud water” and remember: “A hungry fish is a healthy fish?”