Freshwater Aquarium Sharks for Sale

Freshwater Shark Care: Ultimate Guide to Tank, Feeding & Compatibility

Freshwater Sharks are not true sharks, but are typically catfish or relatives of carp. Learn how to take care of freshwater aquarium sharks, food, tank size.

Updated on April 9th, 2026

Care Sheets

Freshwater Semi-Aggressive Fish: Top Secrets for a Thriving Tank

Learn how to care for semi-aggressive fish, recommended diet & aquarium setup. Find the right food, supplies & equipment at your neighborhood Petco.

Updated on April 9th, 2026

Care Sheets

Freshwater Community Fish: Care, Setup & Compatibility Guide

Learn how to care for freshwater community fish, recommended diet & aquarium setup. Find the right food, supplies & equipment at your neighborhood Petco.

Updated on April 9th, 2026

Care Sheets

Freshwater Aquarium Setup: A Step-by-Step Guide for Beginners

Learn how to set up a freshwater fish tank and key considerations regarding placement, supplies needed, and the set up process.

Updated on October 23rd, 2025

Care Sheets

Master Aquatic Plant Care: Lush Aquarium Plants & Happy Fish

Tanks with live plants can be excellent additions to your home, bringing a touch of nature indoors. Learn how to take care of aquatic plants.

Updated on November 6th, 2025

Training & Behavior

My fish are too big for my tanks. What size aquarium do I need?

All these fish can grow quite large. The loach would be the "smallest" at about 6 to 8 inches when full grown. The Oscars can reach lengths of 18 inches and the Texas cichlid and sharks can reach a foot in length. All these fish will require much larger tanks than the ones you have now. The three Oscars alone would do best in a 125 gallon aquarium MINIMUM. The others may thrive in 55 to 75 gallon tanks. To leave them in small tanks will cause stress, aggression and likely infection.

Updated on September 24th, 2025

Vet Q & A

Why are my angelfish and red tail shark sick in their new tank?

Check the water chemistry and temperature. Use a home test kit or submit a water sample to test fro elevated ammonia or nitrite levels. Most pet stores will do this for free or for a small fee. Partial water changes can be done, if indicated, to stabilize chemistry and improve or maintain water quality. Ideally, you want 0 ppm ammonia and nitrites with nitrates at 20 ppm or less in a non-planted tank or 40 ppm or less in a planted tank. Use only aged or conditioned water that is temperature matched to prevent stress or shock. You'll need to keep the temp at the upper limits for Red Tails in order to keep the Angelfish comfortable. That would be in the 78F to 80 F range. Both have similar pH requirements, 6.8 to 7.5. You can fast the Angel for 2-3 days then feed bits of cooked, shelled green peas. This will usually resolve constipation and bloating. Pristine water quality may resolve the patch on your shark. Recommending a medication without more information or a clear image would be risky to the stability of the tank's nitrogen cycle. You can use plain aquarium salt (NOT table or Epsom salt) as a general tonic. It will reduce stress, improve gill function, may treat minor infection and aid in recovery. Dissolve 1 tablespoon per 5 gallons of water in a cup of tank water and gently pour it into the tank. Treat for 10-14 days then reassess the condition. A note on tank size: Although the two fish may be fine in a 15 gallon tank now, you will likely need a larger tank as they mature. Red Tails can reach 6-7 inches and Angels can reach 6-8 inches. At adult size, a 15 gallon tank will be insufficient and could lead to some aggression from either fish.

Updated on September 24th, 2025

Food & Nutrition

What fish and supplies are best for a beginner's small tank?

Without anything to use for scale, it is hard for me to tell how big your tank is, but in general it seems very small. Also, the water that is in the tank appears very cloudy right now, so that would be the first place to start. Water quality is very important, and will make or break your ability to house and care for fish. I would recommend getting a good filter system (you can visit a local pet store to assist you with brands in your area, as I am not familiar with what you can get in India). Be sure to bring the measurements (height, length, width) of your tank, or the gallons or liters so they can tell you what capacity of filter you will need. Everything else will depend on what types of fish you get - if you plan on getting multiple fish, they will need to be small - a general rule of thumb is one square inch of fish per gallon of water. Depending on the species you get, you may need to also get a bubbler to ensure there is enough oxygen in the water for them, and you will also likely need to get some sort of substrate for the bottom and cage furniture (different species have different air requirements, and some are secretive and like to hide). You may also need a water heater, depending on the species you would like to house. But, depending on how small your tank is, it may be hard to get a water heater that will fit. The food type will also depend on what species you get, as there can be differences in diet type between species. I hope that gives you a place to start, and good luck!

Updated on September 24th, 2025

Vet Q & A

Why are my fish dying with bleeding, white spots, and polluted water?

I'm sorry you are having difficulties with your aquarium. There are several issues that should be dealt with right now. They are water chemistry, aquarium size and choice/number of fish. Any new aquarium should be set up and, ideally, run empty for several weeks (usually 4-6 weeks). This is so beneficial bacteria have an opportunity to populate the substrate and filter. These bacteria are necessary to break down wastes that fish will produce. The technical phrase for this is "establishing the Nitrogen cycle". These bacteria will break down wastes into ammonia then nitrites then nitrates. Nitrates can then dissipate or be absorbed/used by live plants. In high enough concentrations, ammonia and nitrites are toxic and can kill fish. Cycling a tank with fish is possible but it increases the risk of loss. Water chemistry should be checked every few days using a liquid home test kit. A water sample can be submitted for testing , but is not as convenient as testing yourself. Most pet stores or fish stores will do this for free or for a small fee. Partial water changes, no more than 30%, can be done as needed to stabilize chemistry and maintain water quality. Choices for water conditioners include NovAqua, AmQuel Plus, Prime, StressZyme or StressCoat. Tank size is another concern. With most fish, the widely accepted "one inch of fish per gallon" will be sufficient. For koi and other carp species, including goldfish, the rule is not sufficient. At full size, goldfish need 20 gallons per fish with an additional 10 gallons for each additional fish. Koi do best in larger tanks, much larger...we're talking in the hundreds of gallons or small ponds. These species produce a larger than average bio-load (wastes) that can quickly affect water quality in a tank. To combat this, large water volumes and powerful filtration are required. Any filter should be rated for at least twice the tank volume. I'm not sure what size tank you have now, it may be fine if the fish are young and small, but they will quickly outgrow it. The last issue is choice of fish. Koi and goldfish are cold water fish. They do best in water between 65F and 72F. Most species of sharks do best in the high 70sF to low 80sF. Keeping fish in incorrect water temperatures will lead to stress and illness. This could be compounded by the water quality/chemistry issues you are having currently. Until the chemistry is stable and water quality is maintained, your fish will continue to become ill and possibly die. Any treatment will not be successful in this situation. Do not purchase or add any more fish until the tank has cycled. If you have additional questions, you can post them in the forum or request a consultation to discuss the case in greater depth.

Updated on September 24th, 2025

Food & Nutrition

What's the best food for my Rosaline Sharks, Congo Tetras, and Pleco?

The Sharks and Tetras can eat a high quality flake food every day. Brine shrimp (either live or frozen) and blood worms can also be offered. Tetra and Hikari are my own recommendations. The Pleco can eat fresh greens or vegetables. Remove any uneaten food after 24 hours to prevent fouling the water. Sinking wafers or pellets can also be offered.

Updated on September 24th, 2025

Freshwater Sharks for Aquariums

Bala Shark

GloFish Galactic Purple Shark

Rainbow Shark

GloFish Cosmic Blue Shark

GloFish Sunburst Orange Shark

Redtail Shark

Albino Rainbow Shark

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