Fishkeeping 101: Can I Add Warm Water to a Fish Tank?

Fishes, be it wild or aquarium, are prone to sudden water temperature changes. That’s what makes a fish keeper meticulous at monitoring the temperature of a fish tank. It could be your broken water heater or temperature fall, and you don’t even know what your next move is.

Well, in most cases, sudden (gradual too) declination of the temperature in your aquarium brings catastrophe. So, it’s really important to keep a fish tank warm while it’s unbearable for your fish.

Worry not. It’s still worth carrying on without a water heater. You can definitely put warm water in a fish tank. Perhaps, an old bottle of soda and a cup of warm water could do the trick for you.

However, it’s an extremely sensitive process given the fact your fish’s immune system is at stake. Keeping the water coherent to the fish’s concurrent temperature will be a challenging task.

So, buckle up and let’s find out how to save your fish from freezing cold and ensure a controlled and healthy atmosphere inside the fish tank.

Choosing the Best Type of Water for Your Fish Tank to Keep it Warm

The first thing you should consider before heating up the water is choosing the type that suits your fish best. The most accessible one is tap water. You can also go for well water, bottled water, distilled water, or even reverse osmosis water.

Can I Put Warm Water to a Fish Tank

However, tap water might be the easiest option, but they come with chlorine in it. Chlorine could be harmful to your fish. So, I would recommend going for distilled water as it comes cheap and is free from harmful ingredients.

How to Warm Up Water before Putting It in a Fish Tank?

Warming up the water for your fish tank is an easy task. You can just boil the water on a gas stove or use a regular water heater to proceed. Boiling the water at its highest makes it safer, but it is not mandatory. You can just Luke warm it to give your fishes a comfortable swim.

There is a rumor about boiling water that doesn’t have oxygen in it for fish to breathe. Well, the myth is busted. Boiling the water does not break the chemical composition of water.

Yes, the living microorganism may not make it through, but you have the same numbers of Hydrogen and Oxygen composition in it.

Just a friendly reminder; don’t put your electric water heater in the fish tank. Your fish are going to die otherwise.

Three Ways of Putting Warm Water in a Fish Tank

Necessity is the mother of all invention. Putting warm water into a cold-water tank is also such an invention that’s saving the night for thousands of fish keepers around. Well, there are actually three conventional methods of putting warm water in your fish tank. These follow-

1. Putting Warm Water Directly In a Fish Tank

Let’s begin with the shortest yet tricky process.

You can put warm water in a fish tank directly. To do so, you may need to take away a few cups of water from the tank. However, make sure you don’t pour too much warm water rapidly. It’s always better to distribute the water evenly.

Putting Warm Water Directly In a Fish Tank

If your fish tank is not that large, you can use a stick to stir the water slowly, making an even distribution. Yeah, try to be slow. Your guppies wouldn’t like to be surprised by warm water out of nowhere no matter how cold it is.

Since we are talking about surprise; you might think why don’t I take away the fish?

Well, I appreciate your sincerity. But don’t do it.

The amount of stress your fishes will be going through while relocating from one place to another will be worth keeping instead. So, make sure the temperature of certain areas, while putting warm water, doesn’t get extremely hot.

The professional recommendation would be around 27 to 32 degrees centigrade temperature inside a fish tank.

2. Using a Bottle of Warm Water to Keep the Temperature Up Inside a Fish Tank

Using a bottle of warm water is perhaps the safest method of warming up your fish tank in the freezing cold. All you need to do is warm the water, put it in an old soda bottle, twirl the cap, and dump it inside the fish tank.

Well, don’t make a blunder. You need to be extremely cautious while doing the process.

Control the immersion of the bottle and let the heat disperse evenly. It would be wise to use two small size bottles at two ends of the fish tank for a healthy setting.

Using glass-made bottles could be a good alternative to plastic ones. It won’t float back even when the water gets cold again. On top of that, it adds aesthetic value to the aquarium!

3. Warming the Fish Tank Keeping the Old Water

Heating up the fish tank by adding new warm water on a frequent basis might swing the mood of your fish. So, you can just take the existing water from the fish tank using a cup, and warm it up. This will eliminate the risk of adding contamination and maintain a static water environment.

What Will Happen If You Put Warm Water Inside A Fish Tank?

Putting warm water in a fish tank brings a few changes.

First of all, your fish will go to the bottom of the fish tank since warm water is desirable to them in extremely cold conditions. Note here that the warmer water is heavier than the existing cold water in your fish tank. So, make the water blend anyway.

What Will Happen If You Put Warm Water Inside A Fish Tank

Secondly, you might find dirt floating around the fish tank. The motion of adding new water to the fish tank will disturb the bed where fish waste hides in. This will create chaos in the first place if you are not gentle with pouring water into the fish tank.

Thirdly, your fish might start swimming around fanatically. The rise in temperature brings changes in fish’s bodies and metabolism. They become more active and get hungry quicker than before.  However, this is a good and prerequisite thing for fish’s health.

Things to Check before Putting Warm Water in a Fish Tank

Putting warm water is not a conventional way of heating up a fish tank. 15 to 20 percent of people fail to do the method which makes it harder for fish to catch up with the temperature.

So, you should check the temperature before, during, and after the process. Try to keep the coherence while making the changes. Checking the quality and composition of the water is also important.

Make sure you don’t have any temperature fluctuation-prone fish on board. Some fishes are extremely sensitive to the slightest change in water temperature.

If you are putting warm water carelessly your fish might catch stress-related diseases.

Alternative Home Remedies for Putting Warm Water in a Fish Tank

Good news is there are numerous alternatives to putting warm water in a fish tank.

1. Bringing Room Heater into Rescue

You can just simply start by turning the heater of your room up. This might be gradual yet a pleasant process. The room heater will not require any extra effort from you and the changes in temperature will be comfortable for the fish.

2. Moving the Fish Tank to a Warmer Area Will Help too

If your fish tank is not that large, you can move it to a warmer area. Moving it near the radiator will be the most beneficial option. However, the temperature near the TV, in higher places, or even the crowded space is slightly warmer and better for your fish.

3. Using Bulbs to Warm Up a Fish Tank

Bulbs or lights are the most commonly used technique followed by the water heater to warm a fish tank. However, LED lights might not be good enough to warm up things. In that case, you might need to go for stronger fluorescent bulbs to give your fish good water to live in.

4. Making a Heat Insulation System to Warm Up Fish Tank

You can use your old blanket, clothes, and thick towels to cover the fish tank. It will help prevent outside breeze or coldness – which could have continuously decreased the temperature – from affecting the aquarium.

This might sound funny, but tell you what, it’s an effective way of keeping the fish tank while the temperature is dropping suddenly.

Some Cold Water Fishes that Can Thrive the Same Even In Water Temperature Fluctuation

After going through all the processes you might want to know which are the fishes that can live on their own no matter what the temperature is. Check them out here –

Cold Water Fish Temperature
Comet Goldfish 60-70°F
White Cloud Minnows 64-72°F
Zebras 70-78°F
Paradise Fish 60-86°F
Variable Platy Fish 61-75°F
Rainbow Shiners 60-80°F
Hillstream Loaches 68-75°F

My Last Two Cents

With winter forthcoming, don’t forget your fish. It’s good to keep a water heater for your fish tank no matter what alternative you go for. A water heater is the most effective and standard way of warming up the aquarium in your house.

However, an emergency or the lack of preparation might make you plump for the warm water. Be careful and gentle on your task while heating up water in a fish tank.

With excellence by your side, it’s absolutely okay to put warm water in a fish tank. Happy fishkeeping!

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