Scavengers - Add one or two fish to keep your aquarium clean

An Otocinclus Catfish is an amazing little scavenger for freshwater aquariums.
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Your description of “flea” perfectly fits the description of Gammarus shrimp, also called scuds or sideswimmers. They are shaped much the same, with a thin but tall body. They grow up to a half inch, though, so they may be too large for your description as “dots.” Scuds arrive as hitchhikers on aquatic plants, and live in the gravel and detritus. Hobbyists often spot them zooming and looping around the aquarium. They, too, are harmless scavengers, and I’d consider them to be desirable. Most fish relish them as a snack. Gammarus shrimp would happily congregate on a freshly dead fish to enjoy a hearty meal.
Nov 12, 2016 - swept away by water currents and scavenging fish. Small scavenger fish can be introduced to a planted aquarium for the same purpose.
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Loaches are traditionally recommended as aquarium cleaning fish, but not all species are suitable for this role and some have to be fed just like other fish. Effective scavengers include coolie loaches, dojo loaches, dwarf loaches and sucker loaches. One caveat about sucker loaches is that when mature, they can nip other fish and may latch onto flat-bodied tank mates in the absence of algae. Here's a Pink Corydoras Catfish for sale in our facility. Click here for more about buying Cory Catfish from us. These are good scavengers for small aquariums.
Photo provided by FlickrThis page contains an index of the Scavenger Fish that are discussed or sold on this website
Photo provided by FlickrHundreds of different fish are well suited to small, freshwater aquariums
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Snails and fish eggs
Keeping the water quality up in a breeding aquarium is often of extreme importance and introducing a scavenger will help you with this. The problem with scavenging fish species is however that many of them like to eat fish eggs. Even fish species that normally stick to an herbivore diet can be tempted by the look of tasty fish eggs. Snails are however much less fond of eating healthy fish eggs and are therefore a good choice of scavenger in a breeding aquarium. The clown loach is referred to as a scaleless fish because it has very small scales that are embedded in its skin. Clown loaches are found in Indonesia around Borneo and Sumatra and are schooling fish that prefer to be with five or six other fish of their own kind. They will tolerate other types of fish in a tank, however. In the wild, clown loaches scavenge for shrimp and other dead fish on the ocean floor. In an aquarium, they feed on freeze-dried, live, or frozen worms. They will eat vegetables but only to complement what may be missing from their diet.Scavenger fish are bottom feeders that eat debris, dead fish, and algae on the floor of a body of water. Scavengers help keep water clean and are a major asset to the environment in which they live. Scavenger fish are great for aquariums as well; they can cut cleaning time and costs.Watch more How to Take Care of an Aquarium videos:

Bottom eating fish are fish that would be catfish, otocinclus, any fish that scavenges off the bottom. Remember, fish in an aquarium are going to eat everywhere. They're going to go to the top of the tank, the bottom of the tank, they're going to nibble on the decoration. They are even going to try and eat the algae on the glass. In an aquarium, you're going to want a fish that predominantly eat on the bottom. Any fish with the morphology of a down-turned mouth, usually is a fish that would scavenge off the bottom. These fish are critical in an aquarium, because they are going to eat a lot of the leftover food. Now, that doesn't mean that you can overfeed, but you should have fish that scavenge on the bottom. Any of the corridors, catfish, pleckos, otocinclus; those are auto-cleaning fish, but they also scavenge waste and uneaten food off the bottom.

Another beneficial thing to have bottom-eating fish is, when they're going about their business, they are kicking up a lot of the waste that settles on the bottom gravel, and allowing the water column to pick it up, where the filtration can eventually filter it out. Having fish with little feelers on their mouth is great, because they're going to go on the gravel and they're going to free up a lot of the waste.

Food, when you feed an aquarium, that food is really only good for an hour or so. After that, it turns to mush. So, it's not like these fish are going to be eating the food all day and all night, but they are helping to probe the bottom of the tank. You want to keep it visually looking great; you don't want to see all the detritus and waste that settles on the bottom. They're beneficial to the aquarium. Any of the small catfish, pleckos, algae eaters, otocinclus; those are the fish you want to go with. Again, they do contribute to the total fish volume in your aquarium, so if you like those mid-water, beautiful, showy fish, only go with a couple of bottom fish, and make sure they're not catfish that get too big. A lot of catfish get really, really big, so you want to make sure that you don't go with anything with a really big mouth; it's going to eat your other tankmates.