How Often Do You Have to Change Water in a Fish Tank?

We hobbyists need to perform water changes often in order to mimic nature. Because wastes are continually being flushed down the drains, most waterways have low levels of nitrates. Unfortunately, nitrates is the side effect of feeding fish. When this parameter is kept low, fish will be at their healthiest.

Generally below 40 parts per million is considered safe for most fish. A simple way to regulate this is by changing water. The act of changing water can be as easy as it sounds. We want water without nitrates to be taken out and replaced with water that has them. I want to be able to control the water quality. Many hobbyists just change their water once a month. You’ll often hear hobbyists say, “change your water every other month.” But there are also those who insist on changing it every week. There are also those weird discus breeders who do it every day! Who is right?

Both are right and wrong at the same moment. They are correct that they have a schedule that works for them. They are all wrong to recommend a particular water change schedule. It is better to show the individual how to assess their water changing requirements. First, we must realize that each tank will have its own water change schedule. This is because each tank will have a different bio-load. The bio-load is determined by the amount of fish and food consumed. It doesn’t take much thought to realize that more fish combined with more food will result in more fish waste. A decrease in fish and food would mean less waste. We need to figure out how much waste we’re producing. You can do this by checking your water for nitrates.

You will be able to see how your nitrates rise each week if you have a well-stocked tank. Once we can track how our nitrates are rising, we can start to regulate it. As an example, I am going to use an aquarium that produces 10ppm of nitrates per week. We want to keep nitrates under 40ppm, as we stated previously. In this example, we can see that after 4 weeks our aquarium hits 40ppm. We must perform a water change. We conduct a 30% water exchange. This will decrease our nitrates 30%. The new nitrate level is now 28ppm. As we know, in another week, our fish will have produced 10ppm of nitrates. Our count will now be at 38ppm. As you can see, we will be changing our water every week in line with current trends.

I prefer to perform a 30% water change on my aquariums when it is time. Although larger water changes may seem better, drastic water changes can cause stress to plants and fish. The goal of changing water is to keep the fish healthy. If a large water change results in stress or illness, it is not meeting our goal. You might be thinking, but I don’t want to change water every week. Don’t worry, you can tune an aquarium to fit your needs.

By feeding less or keeping fewer fish, you can reduce the frequency of water changes. There is also the option of getting a larger aquarium. When you add more water volume to the same amount of fish, you’ll spread the waste out over more water, resulting in fewer parts per million. My last recommendation for combating water changes is to add live plants to your aquarium. As they grow they eat nitrates. Be careful not to fool yourself, most tanks will still need water changes even if you use all these techniques. It is only a matter how many water changes it takes.

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