The simple answer is: There is no need to remove the fish from the aquarium when making a partial water change.
Based on expert advice, removing fish during routine maintenance like a partial water change is generally unnecessary and can cause more harm than good.
Why You Shouldn't Remove Fish During Partial Water Changes
The primary reason for leaving your fish in the tank is to minimize stress. Fish are sensitive to changes in their environment, including:
- Handling: Netting and moving fish can injure their fins or scales and is inherently stressful.
- Water Parameters: The water in a separate container will likely have different temperature, pH, and chemistry compared to their established tank water, even if it's temporary. Rapid shifts in these parameters can be dangerous.
- Habitat Disruption: Being removed from their familiar surroundings can cause anxiety and fear.
As the reference states, "There is no need to remove the fish from the aquarium when making a partial water change, as this would cause more stress for the fish." Avoiding this stress is crucial for their health and well-being.
Performing a Partial Water Change with Fish Present
Performing a water change with your fish still in the tank is standard practice. Here’s how to do it safely:
- Gather Supplies: You will need a gravel vacuum/siphon, a clean bucket, aquarium-safe water conditioner (dechlorinator), and appropriately temperature-matched fresh water.
- Prepare New Water: Treat the fresh water with a quality water conditioner to remove chlorine, chloramines, and heavy metals. Ensure the new water is as close as possible to the temperature of the aquarium water to avoid shocking the fish.
- Siphon Out Old Water: Use the gravel vacuum to siphon out the desired amount of water (typically 20-30% for routine maintenance). Gently move the vacuum through the gravel to remove trapped debris. Avoid chasing or disturbing the fish unnecessarily. They will likely swim away from the siphon.
- Add New Water: Slowly add the prepared fresh water back into the aquarium. Pouring it slowly helps prevent sudden shifts in water parameters and avoids stirring up the substrate too much.
- Monitor Fish: Keep an eye on your fish during and after the process to ensure they are not showing signs of distress.
Tips for a Smooth Water Change
- Be Gentle: Move slowly and deliberately around the tank.
- Avoid Chasing: Don't try to siphon water directly where a fish is resting; they will move when ready.
- Match Temperature: This is perhaps the most critical step to prevent shock.
- Use Dechlorinator: Always treat tap water before adding it to the tank.
- Partial Changes: Stick to recommended partial water change amounts (e.g., 20-30% weekly or bi-weekly) rather than large volume changes, which are more disruptive.
By following these steps and leaving your fish in the tank, you ensure a much less stressful and safer maintenance routine for your aquatic companions.
