How Much Should I Feed My Saltwater Fish?

How Much Should I Feed My Saltwater Fish?

A seemingly simply question that holds disastrous results for the unknowing aquarist.

As a General Rule of thumb Mid-Cities Aquariums suggests you feed an amount of food that can be consumed by your Marine Livestock in twenty (20) seconds or less. From our experience we would prefer you under feed your saltwater aquarium as opposed to overfeed, but why?

Consider the examples below to help demonstrate how overfeeding your Marine Livestock can have horrible consequences for your aquatic system.


Over an extended period of underfeeding your livestock you will begin to show a few tell tale signs. It is common for fish to pace in front of the tank like a puppy begging for attention. This does not mean your fish are hungry. Hungry fish act similar to humans; becoming agitated and more aggressive with one another. Feeding time should be a time of frenzied feeding, not frenzied fighting.

Another clear indicator of underfeeding is the thickness of the fish. When underfeed a fish will visibly become thinner and decrease physical activity to conserve calories.

If any of these signs arise it is easy for the novice aquarist to notice and react. Simply increasing the feeding regiment, moving to a food with more protein, or target feeding the effected livestock are easy ways to get your fish back on the right track.


The major problem of overfeeding your livestock is that there are very few if any ways to notice it occurring. To the general viewer the fish will look plump and we therefore often assume a state of happiness in the aquarium. However, over weeks and even months of excess feedings the organic food will break down into highly toxic ammonia.

Ammonia is extremely toxic for fish. As fish pull water through their gills they absorb the ammonia in the water. The Ammonia quickly reacts in the fish’s internal system and can be seen in the following symptoms:
1. Gasping for breath at the water surface
2. Red fins/gills or streaking on the body
3. Loss of appetite
4. Laying on the rock or substrate

Once an outbreak of Ammonia occurs it is costly and takes time to reduce the levels safely. Each tank is different and will require a different “prescription” based on the levels of ammonia and its current impact on the livestock. At minimum be prepared to complete frequent aquarium maintenance and to use a combination of chemical reduction and bacterial additives.

Ammonia is not the end of a saltwater aquarium, but if not caught early can be the end of your enjoyment of that aquarium.


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