How to Empty an Aquarium Completely and Safely: A Step-by-Step Guide

Emptying an aquarium is a task that every aquarium hobbyist will face at some point. Whether you’re moving, upgrading to a larger tank, dealing with a disease outbreak, or simply need to thoroughly clean the tank, knowing how to safely and efficiently empty your aquarium is crucial for the health and well-being of your fish and the longevity of your tank. This comprehensive guide provides a detailed, step-by-step approach to emptying your aquarium, ensuring the process is as stress-free as possible for both you and your aquatic inhabitants.

**Why Empty an Aquarium?**

Before we dive into the how-to, let’s quickly cover the ‘why.’ There are several reasons why you might need to completely empty an aquarium:

* **Moving:** Relocating an aquarium requires emptying it to reduce weight and prevent damage.
* **Upgrading:** When upgrading to a larger tank, you’ll need to transfer your fish and decorations.
* **Disease Outbreak:** In severe cases of disease, emptying and disinfecting the tank may be necessary to eliminate pathogens.
* **Tank Repair:** Repairing cracks or leaks requires emptying the tank completely.
* **Thorough Cleaning:** While regular water changes are essential, a complete cleaning might be needed to remove stubborn algae or debris.
* **Rescaping:** Sometimes you may want to completely rescape your aquarium and this requires to completely empty it.

**Essential Equipment and Preparation**

Proper preparation is key to a smooth and successful aquarium emptying process. Gather the following equipment before you begin:

* **Buckets:** Several clean, food-grade buckets are essential for holding water, fish, and plants. *Never* use buckets that have been used for cleaning chemicals.
* **Aquarium Vacuum/Siphon:** This tool is used to remove water and debris from the tank. Make sure it’s appropriately sized for your aquarium.
* **Fish Nets:** Soft mesh nets are needed to safely catch and transfer your fish. Have at least two nets available – one for chasing and one for scooping.
* **Large Containers or Bags:** You’ll need containers to temporarily house your fish. These can be large plastic bins, buckets, or even specialized fish transport bags.
* **Air Pump and Air Stone:** To keep the water oxygenated for your fish while they are temporarily housed.
* **Heater:** To maintain a consistent water temperature for your fish in their temporary containers. It’s best to use a heater that you can regulate, or a small, preset heater.
* **Dechlorinator/Water Conditioner:** To treat the new water you’ll be adding back into the aquarium after cleaning.
* **Towels:** Plenty of towels to clean up spills and protect surfaces.
* **Cleaning Supplies (Optional):** A soft sponge, algae scraper, and aquarium-safe cleaner (if necessary). *Never* use household cleaners, as they can be toxic to fish.
* **Power Strip/Extension Cord:** Ensure you have adequate power access for all your equipment.
* **Camera/Phone:** Taking pictures of your aquarium setup before you dismantle it can be incredibly helpful when you’re ready to reassemble it.

**Step-by-Step Guide to Emptying Your Aquarium**

Now that you have all your equipment, let’s get started. Follow these steps carefully to ensure the safety of your fish and the integrity of your aquarium.

**Step 1: Prepare Temporary Housing for Your Fish**

This is the most crucial step. Your fish need a safe and comfortable place to stay while you’re working on the aquarium.

1. **Fill Buckets or Containers with Aquarium Water:** Fill your prepared buckets or containers with water *from* the aquarium you’re about to empty. This is crucial because it maintains the water chemistry that your fish are accustomed to, minimizing stress. Fill them about halfway; you don’t want to overcrowd the fish.
2. **Add Air Pump and Air Stone:** Place an air stone connected to an air pump in each container. This will provide essential oxygen to the water, keeping your fish healthy. Make sure the air pump is positioned higher than the water level to prevent water from siphoning back into the pump.
3. **Add Heater (if necessary):** If your room temperature is significantly different from the aquarium water temperature, use a heater to maintain a consistent temperature. Aim for the same temperature as the aquarium water. This is especially important for tropical fish.
4. **Cover the Containers:** Cover the containers loosely with a lid or towel. This helps prevent fish from jumping out and also reduces stress by creating a darker, more secure environment. Make sure there’s still adequate ventilation.
5. **Choose a Safe Location:** Place the containers in a quiet, dimly lit area away from drafts and direct sunlight. This will help minimize stress for your fish.

**Step 2: Remove Decorations and Plants**

Carefully remove all decorations, rocks, and plants from the aquarium.

1. **Handle with Care:** Be gentle when removing decorations, as they may be fragile or have delicate structures. Avoid dropping them, as this could damage the tank or the decorations themselves.
2. **Inspect for Hitchhikers:** Examine each decoration and plant for snails, algae, or other unwanted organisms. Remove any hitchhikers before placing the decorations in a bucket of aquarium water.
3. **Store in Aquarium Water:** Place the decorations and plants in a separate bucket filled with aquarium water. This will help keep beneficial bacteria alive and prevent the plants from drying out. Add an air stone to this bucket if you plan to keep the decorations and plants out of the tank for more than a few hours.
4. **Consider Delicate Plants:** If you have delicate plants, you may want to store them in a separate container with a small amount of fertilizer specifically designed for aquatic plants. This will help keep them healthy during the process.

**Step 3: Catch and Transfer Your Fish**

This is often the most stressful part for both you and your fish. Patience and gentle handling are key.

1. **Turn Off the Lights:** Dimming the lights or turning them off completely can help calm the fish and make them easier to catch. Fish are less likely to dart around frantically in the dark.
2. **Use Two Nets:** Use one net to gently guide the fish towards the other net. Avoid chasing them around the tank, as this can cause stress and injury.
3. **Be Patient:** Fish can be surprisingly quick and elusive. Take your time and don’t get discouraged if it takes a few tries to catch each fish.
4. **Handle with Care:** Once you’ve caught a fish, gently transfer it to one of the prepared containers. Avoid squeezing the fish or holding it out of the water for too long.
5. **Prioritize Sensitive Species:** If you have any particularly sensitive or delicate fish, catch them first and place them in their temporary housing as quickly as possible.
6. **Observe for Stress:** After transferring the fish, observe them closely for signs of stress, such as rapid breathing, erratic swimming, or loss of color. If you notice any of these signs, make sure the water is properly oxygenated and the temperature is stable. You can also add a small amount of aquarium salt to the water, which can help reduce stress in some species.

**Step 4: Remove the Remaining Water**

With the fish and decorations safely out of the way, you can now focus on removing the remaining water.

1. **Use an Aquarium Vacuum/Siphon:** Insert the siphon into the tank and begin siphoning the water into a bucket. Make sure the output end of the siphon is positioned lower than the water level in the tank to create a proper siphon.
2. **Clean the Substrate (Gravel):** While siphoning, use the vacuum to clean the substrate (gravel or sand). Gently move the vacuum over the surface of the substrate, allowing it to suck up any debris or waste. Avoid digging too deeply into the substrate, as this can disrupt the beneficial bacteria colonies.
3. **Dispose of the Water Properly:** Dispose of the used aquarium water down the drain or in a location away from plants that you would like to keep healthy (the nutrient-rich water can sometimes promote algae growth). *Never* dump aquarium water into natural bodies of water, as this can introduce invasive species or diseases.
4. **Leave a Small Amount of Water (Optional):** If you have a very well-established aquarium with a thick layer of beneficial bacteria on the substrate, you can leave a small amount of water (1-2 inches) in the tank to help preserve these bacteria. However, this is not necessary, and you can safely remove all of the water if you prefer.

**Step 5: Cleaning the Aquarium (If Necessary)**

Whether or not you need to clean your aquarium depends on the reason you’re emptying it. If you’re moving or upgrading, a simple rinse may be sufficient. However, if you’re dealing with a disease outbreak or excessive algae growth, a more thorough cleaning is necessary.

1. **Rinse with Warm Water:** Rinse the inside of the aquarium with warm water. Use a soft sponge or cloth to gently scrub away any algae or debris. Avoid using abrasive cleaners or scrub brushes, as these can scratch the glass or acrylic.
2. **Use Aquarium-Safe Cleaner (If Necessary):** If warm water alone isn’t enough to remove stubborn stains or algae, you can use an aquarium-safe cleaner. Make sure to choose a cleaner that is specifically designed for aquariums and follow the manufacturer’s instructions carefully. *Never* use household cleaners, as they can be toxic to fish.
3. **Disinfecting for Disease (If Necessary):** If you’re emptying the aquarium due to a disease outbreak, you’ll need to disinfect it thoroughly to kill any remaining pathogens. A common method is to use a diluted bleach solution (1 part bleach to 20 parts water). Apply the solution to all surfaces of the aquarium, including the glass, silicone seals, and any decorations that you plan to reuse. Let the solution sit for at least 30 minutes, then rinse the aquarium *very* thoroughly with fresh water. Make sure to remove all traces of bleach before refilling the aquarium.
4. **Rinse Thoroughly:** After cleaning or disinfecting, rinse the aquarium thoroughly with fresh water until all traces of cleaner or disinfectant are gone. It’s important to rinse the aquarium multiple times to ensure that it is completely safe for your fish.
5. **Dry the Aquarium:** Once the aquarium is clean and rinsed, dry it with a clean towel. This will help prevent water spots and make it easier to inspect the tank for any damage.

**Step 6: Reassembling Your Aquarium**

Once the aquarium is clean and dry, you can begin reassembling it.

1. **Inspect the Tank:** Before you start, carefully inspect the aquarium for any cracks, chips, or other damage. If you find any damage, it’s important to repair it before refilling the tank.
2. **Replace the Substrate:** Add the clean substrate back into the aquarium. If you’re using gravel, you may want to rinse it again before adding it to the tank to remove any dust or debris.
3. **Replace Decorations and Plants:** Replace the decorations and plants in the aquarium, arranging them in a way that provides hiding places and visual interest for your fish. Refer to the pictures you took before dismantling the tank to help you recreate the original setup, or get creative and design a new aquascape!
4. **Refill the Aquarium:** Begin refilling the aquarium with fresh, dechlorinated water. Use a dechlorinator/water conditioner to remove chlorine and chloramine from the tap water, as these substances are toxic to fish.
5. **Acclimate Your Fish:** Once the aquarium is mostly full, slowly acclimate your fish back to the tank. Float the bag or container containing the fish in the aquarium for about 15-30 minutes to allow the water temperature to equalize. Then, slowly add small amounts of aquarium water to the bag or container over the course of an hour. This will help the fish adjust to the water chemistry of the aquarium.
6. **Release Your Fish:** After acclimating the fish, gently release them into the aquarium. Observe them closely for signs of stress.
7. **Monitor Water Parameters:** For the first few days after reassembling the aquarium, monitor the water parameters closely (pH, ammonia, nitrite, nitrate) and perform regular water changes as needed to maintain a healthy environment for your fish.

**Tips for Minimizing Stress on Your Fish**

Emptying an aquarium can be a stressful experience for fish. Here are some tips to minimize stress and ensure their well-being:

* **Handle Fish Gently:** Avoid chasing or squeezing fish when catching and transferring them.
* **Maintain Water Quality:** Keep the water in the temporary containers clean and well-oxygenated.
* **Maintain Stable Temperature:** Keep the water temperature in the temporary containers consistent with the aquarium water.
* **Provide Hiding Places:** Provide hiding places in the temporary containers to help fish feel more secure.
* **Minimize Handling Time:** Keep the time that fish are out of the water to a minimum.
* **Observe for Signs of Stress:** Observe fish closely for signs of stress and take steps to address any problems.
* **Use Stress Coat Products:** Consider using a stress coat product when you put the fish back in the tank to help their slime coat heal and to ease the transition.

**Common Mistakes to Avoid**

* **Using Soap or Household Cleaners:** Never use soap or household cleaners to clean an aquarium, as these can be toxic to fish.
* **Overcrowding Temporary Containers:** Avoid overcrowding the temporary containers with too many fish, as this can lead to stress and oxygen depletion.
* **Not Acclimating Fish Properly:** Acclimate fish slowly to the new water to avoid shocking them.
* **Introducing Contaminated Water:** Make sure the water you add back into the aquarium is clean and dechlorinated.
* **Rushing the Process:** Take your time and be patient throughout the entire process.

**Conclusion**

Emptying an aquarium can seem like a daunting task, but by following these steps and taking the necessary precautions, you can ensure the safety and well-being of your fish. Remember to be patient, handle your fish gently, and maintain good water quality throughout the process. With proper planning and execution, you can successfully empty and reassemble your aquarium without causing undue stress to your aquatic companions. Good luck!