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Wondering why you may need CO2 in your fish aquarium? Learn the basics from a Petco aquatics specialist.
Updated on July 17th, 2026
Tanks with live plants can be excellent additions to your home, bringing a touch of nature indoors. There are many varieties of beginner-friendly plants to build your planted aquatic environment. Learn how to build & care for a planted tank.
Updated on October 23rd, 2025
Some fish species generally do well in smaller aquariums, are more adapted to aquarium life, & can be slightly more forgiving with water quality fluctuations.
Updated on June 19th, 2026
Choosing the right substrate for your aquarium is important and provides an area for beneficial bacteria to grow which keeps your aquatic environment safe.
Updated on June 19th, 2026
Learn how to care for Paradise fish, recommended diet and aquarium setup. Find the right food, supplies and equipment at your neighborhood Petco.
Updated on April 9th, 2026
As for what kind of tank you will need: Basically a square fish tank, do not get a bowl. You will likely need a heater and an air pump, and a thermometer, It is easiest to by a complete kit at a pet shop. As for size of tank: The bigger is always the better....however a minimum size will be determined by the type of fish and their average size they will grow into, So once we know what type of fish you have and how many, we can tell you how big your tank needs to be and what type of "furniture" (rocks, plants, gravel) you will need.
Updated on September 24th, 2025
Pimafix is an acceptable "natural" antifungal treatment. Melafix is for bacterial infections. Kanamycin, erythromycin or metronidazole are good broad spectrum antibiotics. Fungus Cure (by API) is an excellent antifungal. You can find these medications in the aquarium section of most pet stores or even online. Follow label directions carefully and remove the carbon filter insert during treatment if indicated. The cornerstone of any treatment is to first maintain pristine water quality and stable chemistry.
Updated on September 24th, 2025
What you have appears to be an aquatic/semi-aquatic species of turtle. Basic requirements include a tank of at least 10 gallons initially, a water heater, a water filter, a basking area out of the water, a heat lamp and a UVB light source.
Updated on September 24th, 2025
Water conditioning can be complicated and I recommend to stop by your local aquarium store. They are most often familiar with the local water quality and can give recommendations specific to your location. Some areas need buffering solutions to help control things like the water pH. Here are a few links which may help answer some of your questions about water condition: https://www.aqueon.com/articles/freshwater-aquarium-water-quality https://www.petcoach.co/article/aquarium-water-management-alkalinity-vs-water-hardness/ Before moving your goldfish, make sure all the conditions are appropriate for goldfish: https://www.aqueon.com/information/care-sheets/goldfish https://www.petcoach.co/article/how-to-help-your-new-goldfish-thrive/ I hope this helps and please feel free to post any additional questions.
Updated on September 24th, 2025
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