How to look after coldwater freshwater fish

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The most common type of fish kept in a cold water aquarium are goldfish, according to the ASPCA. The ASPCA recommends that first-time fish owners buy a cold water fish, because they are the easiest to care for. Other members of the cold water fish family include shubunkins, comets, weather loach and the pearl danio.

Every species of fish comes in different colours and sizes.

Buy all the supplies you need. The ASPCA estimates that setting up for a cold water fish will cost you between £130 and £160. You will need a 20-gallon/75 litre fish tank. Avoid placing your pet in a goldfish bowl or a 10-gallon tank. The ASPCA says that these are too small and will not provide the proper environment to keep your fish alive. You can also buy a timer for the aquarium hood light and set the light to be on for at least 12 hours a day. This promotes healthy algae growth and a balanced aquarium.

Set up your fish tank in a place where it will be kept out of direct sunlight but within range of a power supply to run the filters and aquarium lights. You should place your fish tank on a steady piece of furniture or on a special aquarium stand. Keep it away from noisy and active parts of your house where it can be disturbed. Finally, Aquarium Guys recommend that you keep the tank away from heaters and windows, where changes in temperature may affect the fish.

Install filters before adding gravel to the tank. Then add 4 to 5 inches of gravel to the tank's bottom. Place decorative rocks and ornaments in the tank before filling it with water. Make sure hiding spots exist for the fish to hide in. Fill the tank with tap water. "Run the faucet for about 30 seconds to reduce the amount of heavy metals in the water," to ensure the water is safe, according to the Aquarium Guys.

Purchase three to four small or one to two medium-sized fish to begin your aquarium. When you bring them home from the store, acclimate them to the water by immersing the plastic bag they came in the aquarium's water for 15 to 30 minutes. Open the bag and release the fish into the aquarium.

Feed your fish regularly, but be careful not to overfeed. The ASPCA recommends that you feed dried flakes for a balanced diet and occasionally live brine shrimp, bloodworms and tubifex worms for variety. Avoid overfeeding by feeding your fish small meals several times a day. Be sure they can catch all the food before it lands on the bottom of the tank.

Monitor the water temperature daily. It should be at a constant temperature between 10 and 24 degrees C (50 and 75 degrees F).

Replace the water in the tank every week with conditioned tap water. This will remove chemicals that build up in the aquarium and are not removed by filtration. Scrape away any algae that builds up on the side of the tank and test the water quality with a water testing kit.

Clean the filter and replace the charcoal and the filter pads once a month. Prune any plants that are at the bottom of the tank and be sure the aquarium is kept clean.