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Why Your Fish Aren’t Eating After Water Change

Why Your Fish Aren’t Eating After Water Change

The purpose of this blog is to share general information and is written to the author's best knowledge. It is not intended to be used in place of veterinary advice. For health concerns, please seek proper veterinary care.

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Owning and caring for fish can be an enjoyable hobby, especially when you have exotic fish of all different colors. However, fish are far more than just something beautiful to watch in the background, as they are living beings and need to be taken care of as such.

While you don’t necessarily have to provide maintenance for fish in the same way that you provide maintenance for dogs or cats, it is still important that you research what kind of aquarium maintenance your fish need.

All species of fish are different, with some fish requiring considerable maintenance to keep a good habitat and other fish requiring next to no maintenance.

One of the most important parts of keeping an aquarium in good condition is changing the water out every so often, which is known as a water change. Typically, this is done to clear out dirty and used water from the aquarium, since this is where fish will eliminate and it helps to maintain the overall water balance inside the habitat.

When you are changing the water in the aquarium, it is recommended that you only change 10% to 15% of the water at a time so as not to cause too much of a shock to the aquarium system. There are times when your fish might begin acting differently after a water change, even when you do everything seemingly right.

When fish act differently, such as not eating, after a water change, it often means that something was done wrong in the process and now the fish feels uncomfortable in its aquarium.

It is important to figure out what the problem is when this happens because if your fish doesn’t eat for a prolonged period of time, its health will deteriorate just as quickly.

Checking the Water

The first thing you should do when you change out the water in the aquarium, no matter how little water you are changing out, is to use a water testing kit to ensure that all the levels are where they should be.

Ideally, this is something that you would do after every water change regardless of how your fish are acting.

Doing this will give you a good idea of whether or not the water levels are abnormal for your fish’s needs. All fish have different preferences for the different chemicals in the aquarium that they want, and you should have a good sense of what your fish prefer so that you can keep the aquarium levels at this range.

If your testing kits are older or past the expiration date listed on the box, you should purchase new ones. Old testing kits will not be as reliable as fresh ones and may lead you to believe that the water is safe for your fish when it may not actually be. Here’s what to do if you don’t have a testing kit.

The Dangers of Temperature Shock

When taking out water and pouring new water into the aquarium, it is important that you acclimate the water to be close to what the aquarium’s water would be.

Not only do you need to add the beneficial bacteria to the water you plan to add, but if your aquarium is anything other than room temperature, you will need to match the temperature as well.

Some fish are more sensitive than others, but a large difference in temperature between water sources can be extremely shocking to some common fish, such as the betta fish. While it may take some time to get the temperature right, it will be better for your fish’s health in the long-term to wait it out and acclimate the water.

If you put water in that was too sharp of a temperature difference, your fish may be in a state similar to shock. The way you treat temperature shock will vary depending on the type of fish that you have, but in all cases, it is important to act quickly as temperature shock can be lethal and begins with not eating as the fish either slips into a coma or becomes overheated.

The general course of action for rectifying temperature shock is to do what you can to bring the water closer to the fish’s preferred temperature through the use of heating the tank up and space heaters or by adding fans, chillers, and ice as needed.

You will want to monitor the fish as you make these changes to determine how its health is being affected overall.

Temperature shock can happen at any time when you introduce the fish to water that is too cold or too hot for it, but one of the most common times it can happen is during water changes.

There are other forms of shock that fish can go into if their water rapidly becomes unsuitable, such as pH shock, and the way to approach it is similar. You will want to rapidly try to either decrease or increase the pH level, as the shock can be quickly lethal to the fish.

Preparing Water for Aquarium Changes

Because of how dangerous it can be for fish to be exposed to water that is drastically different than what is in the aquarium, there are some preparations that need to be made when you are preparing the water so that you can minimize the chances that this happens.

Always remember to take your time both with preparing the water and adding it to the aquarium so that your fish are not stressed out by it.

You should make sure that the water you are using is going to be safe for your fish. If you are using tap water from the city, you should pay attention to any events happening with the water that would affect your fish, and if you are using water from a well or similar, you should make sure that the water is clean.

You should already know the pH, chemical, and temperature range that your fish need in their tank, and you will want to prepare the water to be as such. There are many additives that you can purchase from most aquarium-catering pet stores that you can use to reach your fish’s desired ranges.

From here, you will want to slowly introduce the water to the tank so as not to disturb the fish too much. If your fish are used to regular water changes, you should be changing about 10% to 15% of the water on a weekly basis.

On the other hand, if your fish aren’t used to water changes and you are only beginning to do them, you should start with a 5% change at first, as your fish won’t be used to their water levels changing.

As they become more used to the process, you can work your way up to the recommended amount of water.