The short answer is no, you should never do a 100% water change in aquarium. This is because it can disrupt the biological balance of your tank, stress your fish, and cause fluctuations in water parameters. A partial water change of 10-25% every week or two is usually enough to keep your aquarium healthy and clean.
Water changes are an essential part of aquarium maintenance. They help remove waste, toxins, and algae that accumulate in the water over time. These substances can lower the oxygen level, increase the nitrate and phosphate level, and affect the pH and hardness of the water. If left unchecked, they can harm the health of your fish and plants, and cause algae blooms and foul odors.
Water changes also replenish the trace elements and minerals that are used up or filtered out by the plants, fish, and filter media. These substances are important for the growth, color, and vitality of your aquatic life. They also help maintain the stability of the water chemistry and the beneficial bacteria that break down the waste.
How to Do Water Changes Properly?
The best way to do water changes is to use a gravel vacuum or a siphon hose to drain out a portion of the water from the bottom of the tank. This will remove the debris and detritus that settle in the substrate, as well as some of the dissolved substances in the water column. You should aim to change 10-15% of the water every week, or 25-50% every two weeks, depending on the size and stocking of your tank.
Before you add new water to the tank, you should treat it with a water conditioner that neutralizes chlorine, chloramine, and heavy metals. You should also match the temperature and pH of the new water to the old water, to avoid shocking your fish. You can use a thermometer and a pH test kit to check the water parameters. You can also adjust the hardness and alkalinity of the water if needed, using products such as aquarium salt, baking soda, or peat moss.
When you pour the new water into the tank, you should do it slowly and gently, to avoid disturbing the substrate, plants, and fish. You can use a bucket, a pitcher, or a hose to add the water. You can also place a plate or a colander on the surface of the water, and pour the water over it, to reduce the impact.
What Are the Risks of Doing a 100% Water Change?
Doing a 100% water change in aquarium is not recommended, as it can cause more harm than good. Here are some of the risks of doing a complete water change:
It can remove all the beneficial bacteria that live in the water and the filter media. These bacteria are responsible for converting ammonia and nitrite, which are toxic to fish, into nitrate, which is less harmful. Without these bacteria, your tank will go through a new cycle, which can spike the ammonia and nitrite levels, and endanger your fish.
It can stress your fish, as they have to adapt to a sudden change in water parameters, such as temperature, pH, hardness, and salinity. This can weaken their immune system, make them more susceptible to diseases, and even kill them.
It can cause algae growth, as the new water may contain more nutrients than the old water, and the lack of beneficial bacteria may allow the nitrate and phosphate levels to rise. Algae can compete with your plants for light and nutrients, and make your tank look unsightly.
It can waste water and money, as you have to use more water and more water conditioner than necessary. You also have to spend more time and effort to do a full water change, compared to a partial one.
Water changes are vital for keeping your aquarium clean and healthy, but they should be done in moderation. A 100% water change in aquarium is not advisable, as it can upset the biological balance of your tank, stress your fish, and cause water quality issues. A partial water change of 10-25% every week or two is usually sufficient to remove the excess waste, toxins, and algae, and replenish the essential elements and minerals. By doing water changes properly, you can ensure the well-being of your fish and plants, and enjoy your aquarium for a long time.
