Regular water changes are essential for maintaining a healthy and thriving aquarium ecosystem. Here are some reasons why you need to perform water changes:

1. Remove toxins and waste products: Over time, uneaten food, fish waste, and other organic matter will accumulate in the aquarium, leading to high levels of ammonia, nitrite, and nitrate. These chemicals are harmful to fish and can cause illness or death.

2. Maintain water quality: Water changes help to dilute and remove harmful chemicals from the aquarium. This helps to maintain stable water parameters such as pH, hardness, and temperature, which are important for fish health.

3. Prevent algae growth: Algae thrives in nutrient-rich water, which can be reduced by regular water changes.

As for how often you should do water changes, it depends on the size of your aquarium, the number and size of your fish, and the type of filtration system you have. A general rule of thumb is to change 10-20% of the water every 1-2 weeks. For example, if you have a 50-gallon aquarium, you should change 5-10 gallons of water every 1-2 weeks.

When it comes to the amount of water to change, it's important to never change more than 50% of the water at once. Sudden changes in water chemistry can be stressful for fish and can even kill them. Gradual changes are much better for their health.

In addition to regular water changes, there are some chemicals that you'll need to keep your fish healthy and safe. These include:

1. Water conditioner: Chlorine and chloramines are commonly found in tap water, and they can be harmful to fish. A water conditioner can neutralize these chemicals, making the water safe for fish. We suggest Seachem Prime or Aqua One Helth Plus here is our range

2. Ammonia and nitrite remover: These chemicals can build up quickly in the aquarium and cause harm to fish. Ammonia and nitrite removers help to keep these levels in check.

3. pH stabilizer: Fluctuations in pH can be harmful to fish. A pH stabilizer can help to maintain stable water parameters.

4. Algae remover: If you're struggling with algae growth, an algae remover can help to reduce it. Here is some our range

It's important to follow the instructions carefully when using any chemical in your aquarium. Too much of a chemical can be harmful to fish, and not enough may not be effective.