Two Easy Ways to Start Earning Rewards!
Earn 2X Pals Rewards points at Petco
when you use Petco Pay!
Get It Today
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 a Koi, recommended diet and aquarium setup. Find Koi for sale, supplies and equipment at your neighborhood Petco.
Updated on April 9th, 2026

Updated on March 4th, 2026
Feeding your freshwater fish isn't as simple as adding a pinch of flakes! Read these three tips to learn more about how to provide your pets the nutrition and environment they need.
Updated on July 17th, 2026
Learn how to pick the right aquarium plants, substrate, lighting, and fertilizers to ensure that your aquarium plants thrive and stay healthy.
Updated on July 17th, 2026
Check the water chemistry. The discoloration could be due to elevated ammonia levels which can cause "burns". Use a home test kit or submit a water sample for testing. The local Petco may do this for free or for a small fee. Aim for an absence (0 ppm) of ammonia and nitrites with nitrates at 20ppm or less. Perform partial water changes to stabilize chemistry and/or to improve water quality. Use only conditioned water that is temperature matched to prevent stress or shock. The Neons (blue fish) appear to be infected with Ich, a parasite. Treatment is possible with commercial products found in the local Petco. Follow label directions carefully. You will need to treat the entire tank until all traces are gone. Removing a lump from your fish on your own is never recommended. You can cause severe injury. Most broad spectrum antibiotics (Kanaplex, Maracyn, Maracyn 2, etc.) found in the aquarium section of the local Petco should help treat or prevent infection. Choose one and follow label directions. Remove the carbon filter insert during treatment if indicated. Maintain pristine water quality via filtration and regular partial water changes to aid in recovery. You can feed frozen worms, just thaw then first in a small cup then place them in the tank.
Updated on September 24th, 2025
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
This could be bacterial or parasitic infection. It is difficult to determine definitively since the image provided is not clear. Fish can be difficult to photograph. Basic care includes checking water quality and chemistry. This can be done using a home test kit or by submitting a water sample for testing. The local Petco may do this for free or for a small fee. There should be an absence of ammonia and nitrites with nitrates at 20-60 ppm. pH should be as close to 7 as possible, avoiding large swings. Koi can tolerate a wide range in temperature, but generally do best between 65 F and 75 F. Again, avoid large swings in temperature to prevent stress or shock. If necessary, a partial water change can be done to stabilize chemistry and/or improve water quality. If you have other koi, consider placing this one in a hospital tank to make treatment easier and to prevent spread if the condition is infectious. Plain aquarium salt (NOT table or Epsom salt) can be used to reduce stress, improve gill function, treat minor infection and aid in recovery. Dissolve 1 tablespoon per 5 gallons of water in a cup or two of tank water and gently pour it into the tank. Treat for 14 days then reassess the condition. If there is no change, consider a broad spectrum antibiotic or "all in one" treatment. Either can be found in the Aquarium section at Petco. Follow label directions carefully and remove the carbon filter insert during treatment if indicated. All that said, if the spots multiply and appear like tiny grains of salt, it could be an ich infection. In this case the entire tank will require treatment. There are several commercial ich medications that can be used. You will also need to thoroughly vacuum the substrate/gravel in the tank and wipe down all tank furniture.
Updated on September 24th, 2025
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
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