Why Your Fish Might Be Sitting at the Bottom of Your Aquarium

One of the most interesting aspects of the fish keeping hobby is getting to learn about the great diversity of tropical fish. Despite their relative lack of communication with humans, aquarium fish often exhibit behaviors that can have different meanings. When you see fish spending considerable time at the bottom of a tank, it could be for reasons that vary from typical species behavior and water quality to overstocking and health conditions. Let’s look at some of the most common situations.

Bottom Feeding Species

If you have enough room for bottom dwellers such as Corydoras, Plecostomus, and other aquarium catfish, you should by all means welcome them into your tank. These fish will always stay close to the substrate because that’s where they feed. Moreover, they’re scavengers that help in terms of keeping the ecosystem clean by consuming algae. Most of these species are nocturnal, so make sure to turn off aquarium lamps for at least 10 hours each day, optimally 12 hours.

Diurnal Fish

With the exception of bottom feeders, invertebrates, catfish, and some eels, most fish are active in the daytime and require sleep cycles at night. Many of these species claim a spot at the bottom of the tank where they can feel comfortable as they sleep. If you forget to turn off the aquarium light at night, you may see more fish near the bottom during the day because they’re trying to adjust their cycles.

Lethargic Fish

Fish are mostly static when they sleep near the bottom. If you see them swimming very slowly and bumping into the bottom feeders during the daytime, this is a sign of lethargy, which could be caused by inadequate water conditions or a lack of sleep. When you notice lethargic behavior, your first step should be to check water chemistry and temperatures. If you’ve accidentally dropped too much food in the tank or pond, water quality might have decreased, thus requiring a partial water change. Always test your aquarium to know more than just guessing.

Higher Water Temperatures

When fish look healthy but still congregate near the bottom, this collective behavior may have been caused by a change in temperature. Tropical fish enjoy water temperatures in the range of 76 to 80 degrees Fahrenheit, but they’ll seek the cooler depths of their habitats when temperatures rise.

Ich Disease

If you notice fish trying to rub themselves along the bottom and against rocks, this could be a case of Ichthyophthirius or parasites. White spots on top of scales are the most common symptom, along with scratching. This disease can be controlled with chemical formulas sold at the store where you acquire your other fish tank supplies, and you can prevent it by using special water conditioners when doing partial water changes. Remember to add the same temperature water as what came out of the tank.

Watching for fish that are acting abnormally is just one of the many things you must do when caring for an aquarium. It’s absolutely crucial to have all of the essential supplies on hand to ensure your fish remain healthy and happy for many years to come. Whether you need a dosing pump, filtration, beneficial bacteria, LED lighting, or any other aquarium supply, you can find what you need at Aquatic Warehouse. Stop by our store in Kearny Mesa, check out what we offer on our website, or give us a call with any questions at 858-467-9297.