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Beginners Guide

Why And How Often Should You Do Water Changes In An Aquarium

by Nguyễn Hoàng Anh Tuấn 10 Mar 2023 0 Comments

Changing the water for the aquarium is very important to keep the fish and plants healthy. We know the importance of water changes when maintaining a planted aquarium.

At the end of this blog, there will be 5 step instructions to make a quick and easy water change.

Every aquarium's water change is different; this blog includes general instructions for everyone to make the best water change process easy and saving your time. Keep reading to understand your tank's needs for a water change!

Tips: If you're a beginner, we recommend starting with a small aquarium until you understand the water parameters and how they affect your livestock. If you want advice on adding fish to your tank for the first time, read this article here.

Aquarists often complain about algae problems in their aquarium tanks. The main reason for the rapid growth of algae is keeping the water the same regularly. However, it can be easily overcome by increasing the frequency of water changes.

The main reason for the rapid growth of algae is not changing the water regularly

Do you have an accurate estimate of the percentage of water removed and added water? How often do you decide to do a water change in the tank?

The more pets you have, the greater the biological load. You may need to do more water changes more often. And the answer to preventing algae from growing fast is weekly maintenance of your aquarium, which also helps you prevent other problems such as fish diseases, skin sores, etc.

✔️ Tanks with small fish populations and robust filtration systems (including nano tanks) can change the water 15-20% less weekly.

✔️ Larger tanks with large numbers of fish will require a weekly 30% - 50% water change.

✔️ You should change the water regularly during the first month (2-3 times per week) until your aquarium tank can stabilize on its own

Changing the water is vital for maintaining a healthy and lush aquarium. And this is mandatory unless you no longer want to keep fish anymore.

You will need the following:

A sizable empty bucket of about 5 gallons of the standard to let the old tank water flow in.

Siphon vacuum cleaner - means for removing water from the tank

dechlorination machine

Water test kit. In the Micro Aquatic shop, we have two options for your choice, depending on what you need for your tank. To get to know more, check here.

To calculate the percentage of water you take out of the tank, you need a bucket with a rating line, or you can also mark the amount of water on the bucket. The siphon can be a simple piece of the air duct.

When adding water back to the tank, raise the bucket above your aquarium and use the siphon to pull the water from the bucket into your tank. This helps the aquarium get a slow flow, helping the water parameters to be suitable, comfortable, and smooth.

Water quality

It is necessary to consider your tank's water parameters and the water you will add to it during the water change.

You must remove high levels of accumulated chemicals (such as nitrates) and toxins through water changes. You must learn about tap water before exchanging water unless you use pure reverse osmosis water.

Aquarium test kits will help you understand the critical water parameters of tap water, such as pH, ammonia, and nitrate. Once you have established a baseline for your tap water, you can adjust the water parameters to match what you need for your aquarium.

PH refers to the acidity of your tank water. Your tank must establish the correct pH balance for your pets to thrive. Consider many factors, including rocks or other rigid materials, that can affect the pH balance in your aquarium. We recommend testing the water in your tank every few days after a water change.

KH (carbonate hardness) and GH (general hardness) are affected by your pH level. The pH level is proportional to the GH level. An imbalance in these parameters can harm some fish in your aquarium, so ensure these parameters are after a water change.

Be aware of the ammonia and nitrate levels in your aquarium. Ammonia is produced from fish waste, which converts to nitrite. This nitrification process in your tank can harm your pets when it's out of balance. While nitrates are generally harmless, they can become problematic if they build up in your aquarium.

You can prevent this by conducting regular water changes and having enough plants to regenerate the natural ecosystem, which can easily maintain the chemical balance in your tank.

Nitrification cycle

Please note the fish's behavior after the water change process. For example, water parameters are only manageable if they complete the food. In addition, other factors affect the water parameters in the tank, such as complex landscapes, vegetation, and waste..... You should check these parameters regularly to avoid complications.

Dechlorinate your water

Chlorine in water can destroy your plants and harm your aquarium fish. For best results, you must de-chlorinate the water before adding the new water to your tank to avoid damaging your pets.


After water dechlorination, the temperature is an important parameter that needs to be monitored throughout the water change. Many fish and shrimp species can be sensitive to rapid temperature changes. Sometimes just 5 degrees change in the water can cause heat shock to your aquarium fish.

How do you make sure the temperature in the aquarium is constant?

Use a heater for de-chlorinated water so that the new water in the tank suits the temperature of shrimp and fish.

5 Easy Steps to Change Water

Once you've prepared the equipment and understand the importance of water parameters, here are the easy and quick steps to change the water.

  1. Prepare your new water. Ensure you've given enough time, sometimes up to 24 hours, to get the water parameters right for your tank before proceeding to the next steps.

  1. Prepare your tank. Turn off any equipment that may be exposed to air during the process (filters, CO2, heaters).

  1. Clean your tank. Cut dead and dying leaves, then use a net to remove as much water as possible before absorbing the water. We recommend using Up Aqua Planting Scissors for easy pruning.

  1. Drain the old tank water into your bucket and vacuum the surface. While removing the water from your tank, keep the tip of the gravel vacuum close to the substrate to remove accumulated waste tank water and other toxins. Carefully vacuum through your entire substrate to remove as much waste as possible. This is also the perfect time to eliminate any other aquatic plant waste left in your tank after pruning.

If you have small fish or darwin algae in your tank, keep an eye on them when siphoning. You don't want to suck them out of your tank accidentally. It's time to suck out the waste. Place the nozzle close to the gravel surface in your tank. Remember to clean the surface of the glass and the surrounding area.

  1. Add new treated water to your tank. Double-check that the water parameters and temperature are correct! Ensure the siphon introduces a slow and steady stream of fresh water into your tank. Once done, you can turn your devices back on (filters, CO2, heaters). Keep an eye on the water parameters in your tank every few days later.

Hey, are you still there at the end of this blog? Remember to SUBSCRIBE to our shop to get a new topic with helpful information for your aquarium tank. Grab the Hot Deal - Flash Sale daily on our website: Microaquaticshop.com.au.
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