There are several different factors that can influence the water quality and clarity within an aquarium. There are chemicals on the market that can easily clarify a tropical fish tank, but they may simply mask the true cause of the cloudiness rather than address it head on. This list of steps is designed to get to the bottom of what is causing cloudiness in a tropical fish tank.
Determine how long the fish tank has been cycled. The cycling process allows the filter's biological elements to prepare themselves to handle fish waste. If the tank has only been cycled for a couple of weeks or if the tank recently received more fish, then the cloudiness likely results from the cycling process. The only thing needed to deal with this cloudiness is patience, as it will typically remedy itself within three to five days. If cycling the tank is not the problem at hand, continue the diagnostic process.
Check all of the equipment and decorations in the fish tank to see if colour or cloudiness is coming from something inside the tank. This is often the case if there are no fish in the tank. If there is any equipment or decoration in the tank that has not been properly rinsed with cool tap water prior to its introduction to the fish tank, remove the item and clean it thoroughly. The filter equipment in the tank should clear up any floating debris in the meantime. The cloudiness may also be removed by way of weekly water changes if the filter does not remedy the entire problem.
Check the quality of decorations and substrate in the tank to see if anything is breaking down or dissolving. Some items that are not aquarium safe can break down in the water, causing cloudiness and potential harm toward the fish. Remove the item from the aquarium and perform a large water change. Aquarium decorations should be purchased from reputable pet retailers to ensure aquarium safety. Decorations not intended for aquarium use may flake apart or lose paint when submerged in water for a period of time.
Address what chemicals have been added to the aquarium in recent days. Some chemicals can react poorly with other chemicals, creating different types of cloudiness in the water. Prevent this type of cloudiness by minimising what chemicals are introduced to the tank. To determine what chemicals are reacting, mix different aquarium chemicals in small dishes of water to see which chemicals are creating the cloudiness.
Address whether or not the fish in the aquarium are being overfed. Some fish are hardier than others, and finding the right amount of food to offer can be difficult when an aquarium is first started. Overfeeding a fish aquarium can lead to cloudiness in tanks that have been set up for some time. If there have been no other changes in the aquarium that may have caused cloudiness, attempt lessening the amount of fish food offered for a weeklong period to see if the cloudiness improves. Changing the type of food may also be useful, as certain foods can cause cloudier water than others.