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GloFish are brilliantly colored and beautiful fish. Learn how to care for GloFish, what to feed them, how long they live, their ideal tank size and more.
Updated on April 9th, 2026
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
Learn how to safely handle your aquatic life to avoid toxin & bacterial exposure. Find aquatic life care supplies at your neighborhood Petco pet care center.
Updated on October 23rd, 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 April 9th, 2026
Learn how to care for Rainbow fish, recommended diet and aquarium setup. Find the right food, supplies and equipment at your neighborhood Petco.
Updated on April 9th, 2026

Thanks for your question about your fish, and congratulations on your new family members! I didn't see how recently the tank was set up, but there are a couple of things that could be going on. I would start by checking your water quality - any abnormalities in water quality can make fish have abnormal behaviors, and the water looks a bit murky in the photos you provided. There may be parameters that need to be addressed depending on what you find. If you do not have a water quality kit, they can be purchased at the pet store or an aquarium store, or you can take a sample of your water in for evaluation to these places as well. Some will charge a small fee for this service, just so you are prepared. Also, with recent tank set ups, it can be stressful for fish as they are in a new habitat. I would recommend keeping the light on for only a few hours per day to start, as the bright lights can be shocking for them (since fish don't have eyelids). Gradually you can increase the length of time that the lights are on so that you reach a cycle of 10-12 hours of light and 12-14 hours of darkness for them. I hope this gives you a place to start, and I wish you and your mom the best with the new pets!
Updated on September 24th, 2025

I am sorry your goldfish passes away. IT is most likely nothing you did wrong. I would be concerned that the fish was sick before you every purchased it. Sometimes from local pet stores the fish are sick and the stress of transport can cause them to pass. I would contact the pet store and ask them if they have had any other fish pass away. I am so sorry for your loss
Updated on September 24th, 2025

Gold fish can make great fish but they can live up to 25 years and require a large tank that may need to be upgraded if they grow too large. Do get at least 2 fish. Here are some links which may help: https://www.petcoach.co/article/chewing-in-puppies-how-to-control-it/ https://www.aqueon.com/information/care-sheets/goldfish https://www.hartz.com/how-to-introduce-new-fish-into-your-aquarium-tank/ I hope this helps and congrats on your new pets!
Updated on September 24th, 2025

The bloating could be infection. It may also be parasitic infection, constipation or swim bladder disease. You cannot discount them being gravid (pregnant). Glo fish are egg layers, so they could be females readying to spawn (release eggs). First check water chemistry and quality. Clean water is critical to having healthy fish or to having fish recover from illness or injury. Use a home test kit or submit a water sample for testing. Most pet stores will do this for free or for a small fee. An established tank will have 0 ppm ammonia and nitrites with a nitrate level of 20 ppm or less. If your tank shows any level of ammonia or nitrites, perform a partial water change (no more than 30% total volume at a time) using conditioned water. Makebsurebit is temperature matched as well to prevent stress or shock. Glofish do best between 72 F and 80 F. Once water quality is squared away, fast the fish for 2-3 days, then feed tiny bits of cooked and shelled green peas. This will help with constipation and bloating. Feed peas until they are swimming normally and the bloating is resolved. If the peas don't help, try broad spectrum antibiotic, such as erythromycin or ampicillin. You can find either in the aquarium section of the local Petco. Follow label directions carefully and remove the carbon filter insert during treatment if indicated. An "all in one" product, such as Lifeguard (by Tetra) can also be used. This will treat multiple types of infection with one medication.
Updated on September 24th, 2025

Before you buy any fish, you will need to set up the tank. A basic set up includes: a tank, filter, hood/light, heater, gravel and some decor. The tank should run without fish for at least 4 to 6 weeks. This gives it time to cycle. The Nitrogen Cycle is critical to the health of the tank and any fish you will be keeping. During this time, beneficial bacterial will populate the filter and substrate (gravel). These bacteria will be responsible for breaking down fish wastes and other wastes (uneaten food, dead plants, etc.). You will need a home test kit to monitor water chemistry (ammonia, nitrites, nitrates, pH) or you will have to submit water samples for testing. Most pet stores will do this for free or for a small fee. At first, you will see high levels of ammonia and nitrites. Over time, as bacteria grow, these levels will drop. When ammonia and nitrites are at 0 ppm and nitrates are below 20 ppm, you can consider adding fish. Regular (every 1 or 2 weeks) partial water changes as well as filter changes will be needed to maintain stable water chemistry and adequate water quality. The size of your tank will determine what fish and how many you will be able to keep. Most Tetras do best in groups, so a 12 inch tank may not be large enough. There are several article in the Petco Pet Education Center, formerly Petcoach Library that will provide more detailed information. Click on "Educational Center" at the top of the page, then scroll down to "Articles" and click. Use the Search Bar to find articles regarding aquarium set up and fish keeping.
Updated on September 24th, 2025