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Learn how to care for brackish water fish, recommended diet & aquarium setup. Find the right food, supplies & equipment at your neighborhood Petco.
Updated on November 13th, 2025
Learn how to test your aquarium water. Poor water quality stresses fish, which leaves them susceptible to disease and possibly death.
Updated on November 13th, 2025
Learn how to care for semi-aggressive fish, recommended diet & aquarium setup. Find the right food, supplies & equipment at your neighborhood Petco.
Updated on November 13th, 2025
Learn how to pick the right aquarium plants, substrate, lighting, and fertilizers to ensure that your aquarium plants thrive and stay healthy.
Updated on November 13th, 2025
Learn how to care for large marine fish, recommended diet and habitat setup. Find the right food, supplies and equipment at your neighborhood Petco.
Updated on November 13th, 2025
The brown marks are likely diatom growth. You can rid the tank of them by confirming or providing adequate filtration, increasing water motion (use powerheads to create current), remove any tank furniture and scrub with a stiff brush or bleach it, perform a 30-50% water change before returning tank furniture, regulate light exposure (use a timer on tank lights), repeat this process every 2 weeks. You will see less diatom growth after each cleaning. If possible, consider moving the goldfish into a larger tank, at least 75 gallons if you have the space.
Updated on August 12th, 2025
Check the water chemistry. Confirm ammonia and nitrite levels are 0.25ppm or less and nitrates are 40ppm or less. Use a liquid test kit or submit a sample for testing. Most pet stores or aquarists will do this for free or for a small fee. Partial water changes, about 30% can be done to decrease high levels. Use only aged or conditioned water that is temperature matched to prevent further stress or shock. My preferences for water conditioning are AmQuel Plus and NovAqua in addition to StressCoat. Confirm water temperature between 78F and 80F. You can soak pellets in some garlic juice to stimulate his appetite.
Updated on August 12th, 2025
Thanks for reaching out. This problem is perplexing, but possibilities include fungal or bacterial overgrowths. A good cleaning might help to alleviate your problems. Continue to test water quality and correct problems. Sometimes the over-growth of anaerobic bacteria (those which grow in low or no oxygen conditions, at the bottom of the tank), can form strange formations of detritus. Submitting a sample to a lab might help determine an answer. Good luck.
Updated on August 12th, 2025
Check water chemistry and filtration. Sunny may have developed a bacterial or fungal infection due to the switch in environment. Clean water is crucial to resolving infection. Perform regular partial water changes. Use only aged or conditioned water that is temperature matched to prevent further stress or shock. Maintain water temperature between 75 F and 72 F. Minor infection maybe resolved using plain aquarium salt (NOT table salt). Salt is a great general tonic. It reduces stress, improves gill function and aids in recovery. Dissolve 1 teaspoon of salt per gallon of water in a cup of tank water and gently pour it into the tank. Treat until symptoms resolve. When performing water changes, use just enough salt to treat the water being replaced, not the entire tank volume. If necessary, you can use a broad spectrum medication if symptoms persist. Look in the aquarium section of the local pet or fish store for products such as Kanaplex, Maracyn or Lifeguard by Tetra. Follow label
Updated on August 12th, 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 sto
Updated on August 12th, 2025