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  • This is a common misconception. It is actually water quality that stunts growth in fish, not the size of the aquarium. Since nitrates and other pollutants, which act as growth inhibitors, accumulate more rapidly and to higher concentrations in smaller aquariums, they have a greater impact on fish growth and health in small aquariums. Providing proper filtration and performing frequent partial water exchanges will maximize growth and health in your fish regardless of aquarium size.
  • A general rule of thumb is one inch of adult fish per net gallon of water, but activity level, territoriality, available habitat and filtration should also be taken into account. Remember, the average aquarium holds less water than its designated size once gravel and decorations are added. (For example, a fully decorated 10 gallon aquarium holds about 8 gallons of actual water). In addition, most fish that are purchased are going to grow, and some fish just need more personal space, so plan ahead. Always consult an aquarium expert when adding new fish to your aquarium.
  • Feeding depends on the type of fish you own. Aside from large predatory fish, most aquarium fish do best when fed only what they can consume in 2 minutes or less, once or twice a day. Any leftover food will pollute the water and stress your fish. Herbivorous (vegetarian) fish need to eat more frequently, but still feed only small amounts per feeding. Many experienced aquarists skip feeding their fish once or twice a week to allow them to clear their digestive systems. Watch our short video on the 3 Tips to Succeed to learn about the key tips we recommend in fishkeeping.
  • Water changes dilute toxins that naturally accumulate in the aquarium. There are many philosophies about frequency and volume, but small water exchanges done frequently are generally considered best for maintaining healthy conditions in your aquarium. A 10% water exchange done weekly is ideal, however, changing about 25% of the aquarium water once or twice a month is sufficient for most aquariums. Avoid changing more than 50% of the water in your aquarium. In doing so you can dramatically change the aquarium water parameters (temperature, pH, chemistry). Major changes to the aquarium environment should be done slowly so fish have time to acclimate. Watch our video on The Importance of Water Changes.
  • The frequency of how often a filter cartridge should be changed will vary according to how much waste and free-floating algae is in the fish tank. The general recommendation is to change the filter cartridge once per month.
  • Filled aquariums weigh approximately 10 lbs. per gallon. For example, a 20 gallon aquarium will weigh about 200 lbs. once filled with fish, substrate, décor and water. Most household furniture will likely only support aquariums of 5 gallons or less. Aquariums that are larger than that should be placed on a stand or base manufactured specifically for aquarium use and designed to safely withstand the weight of a filled aquarium.
  • Aquariums containing live plants should receive 10-12 hours of high-quality light per day. Tanks with artificial décor only need 5 to 8 hours per day. Hours of light should be the same each day as fish rely on a daily rhythm for their activity and proper health. Use a timer to provide a consistent day/night cycle and never leave the aquarium light on all the time.
  • Algae is nature’s way of purifying water and grows when there is an abundance of nutrients (from fish waste, uneaten food, plant debris, etc.) and light. To keep algae to a minimum, provide proper filtration, feed your fish sparingly, do frequent but small partial water exchanges and avoid excessive light from windows or leaving the aquarium light on too long. Algae eating fish like plecostomus, otocinclus and flying foxes will also help keep algae under control. Watch our short video on the 3 Tips to Succeed to learn about the key tips we recommend in fishkeeping.
  • There are different views on this, but in general, as long as rocks are sterilized and are not calcium based, you can put them in your aquarium. Scrub them thoroughly and either boil or soak them in a mild bleach solution – rinsing thoroughly afterward before placing them in your aquarium. Calcium based rocks are usually white in color and may raise pH and alkalinity to unsafe levels. They should only be used in African cichlid aquariums. To find out if a rock is calcium based, place a few drops of white vinegar on it; if it fizzes, the rock is probably calcium based.
  • There are many reasons for cloudy water. Newly set up aquariums may turn cloudy because of a biological imbalance and will usually clear in a few days if left alone. Do not add any new fish or do any cleaning of the tank or filter. Established aquariums can turn cloudy because of overfeeding, too many fish or inadequate filtration. Adding a larger or second filter, removing some fish and/or cutting back on the amount of food entering the aquarium will often resolve this problem. Also make sure that you are doing regular, at least monthly, water changes. To learn more, watch our video on The Importance of Water Changes.
  • There is no single filter that fits every aquarium need. Typically, hang-on-back filters work well for beginning aquarists because they provide all three types of filtration – mechanical, biological and chemical – and most models use drop-in cartridges, making them very user friendly. Internal filters go inside the aquarium, allowing users to place the aquarium where space is limited. Canister filters can be loaded with virtually any filter media, making them the most versatile type of filter. They take a little more time and effort to service but do not require cleaning as often as other types of filters. Tanks with messy fish should have good mechanical filtration, while heavily populated aquariums should have extra biological media. To ensure optimal performance, choose a filter rated one size larger than your aquarium.
  • There are advantages to both, and you’ll get different opinions depending on who you ask. Glass tanks are more durable, do not scratch easily and because of their strength they can be set on open top stands, which are more affordable. Glass aquariums have open tops, making them easier to decorate and clean. They tend to be more affordable, especially in sizes less than 300 gallons. Acrylic tanks scratch more easily and some may yellow over time. The entire bottom must be supported to prevent bowing and separation of seams. They are lighter and are available in a wider range of shapes than glass aquariums. They can also be easily drilled to accommodate custom plumbing.
  • Fish don’t have eyelids to close, but they do go into a state of rest and reduced metabolism at night, so yes most fish do sleep. Some fish even settle to the bottom at night, and can be picked up by hand. Others remain on alert for danger while in “sleep” mode. Fish that need to keep swimming to breathe, like certain species of sharks, as well as blind cave fish, never sleep.
  • Actually, the process of “cycling” does not begin until fish or a culture of nitrifying bacteria are added to an aquarium, but the longer you wait to add the first fish after initially setting up your tank, the better. Most aquarium experts recommend waiting at least 48 to 72 hours. Always check temperature and test for pH and ammonia first, as many municipalities add chloramine to tap water and a single dose of water conditioner does not always fully neutralize the ammonia.
  • It depends on the type of fish you have! Discus, wild caught angelfish, uaru and certain other fish that are found at or near the equator do better at temperatures between 84° and 88° F. Betta fish thrive best in water temperatures between 76° and 85° F. Most tropical fish prefer temperatures ranging from 76° to 80° F. Goldfish, koi and other coldwater fish prefer the temperatures be between 65° and 72° F. Research the particular fish before determining what temperature to keep the aquarium! Visit our care sheets to learn more about specific types of fish.
  • New livestock purchases should be slowly acclimated to the temperature and water chemistry of your aquarium. Turn off the aquarium light and float the bag containing new fish inside your aquarium for 15 minutes to equalize temperature. Keep the bag closed during this process. After 15 minutes, open the bag, roll the top edge down a few times to form a floatation ring and add a small amount of aquarium water to the bag. Continue adding small amounts of aquarium water to the bag every 5 minutes. After 20 to 30 minutes, gently net the fish out and place them in their new home. Discard the water from the bag, do not pour it into your aquarium. Leave the tank light off for an hour or two to allow the new fish to get used to their new home. An alternate method is to place new fish with their shipping water in a clean container and drip water from your aquarium into the container using air hose and a plastic control valve. Drip rate should range from 1 to 2 drops per second for small bags to a slow dribble for larger bags. After 20 to 30 minutes, gently net the fish out and place them in your aquarium. Leave the tank light off for an hour or two to allow the new fish to get used to their new home.
  • No, simply seeing condensation inside your Aqueon Glass Adjustable Heater does not that it is broken or defective. Check that the heater is working properly by using a thermometer with your fish tank. (also make sure that the water is the right temperature for the type of fish that you have inside your fish tank). The reason you may see condensation is because humidity was in the air and trapped inside the tube when it was manufactured and sealed. Your heater is still able to perform properly with this condensation.