How to Acclimate Guppy Fish?

Disclosure: When you purchase something through my affiliate links, I earn a small commission. As an Amazon Associate we earn from qualifying purchases. read more

So, you’ve decided to get your first guppy pair, you’ve prepared the tank, and got the fish. The first problem you’re facing right from the get-go is understanding the importance of the acclimation process.

Guppies are typically adaptable and resilient fish, but sudden environmental changes can hurt and even kill them.

So, what is the acclimation process, how does it work, and how should you apply it? Let’s see what we can find out!

Why Do You Need to Acclimate Guppies?

Most people know that guppies can withstand impressive variations in their environmental conditions. What they don’t know is that guppies’ adaptability only refers to slow and gradual changes, not sudden ones.

Moving your guppy from the bag or bucket straight into the tank upon purchase can kill the fish rather quickly. That’s because you have no idea about the guppies’ previous environment and what they’re used to.

You’ve probably purchased the guppy from the seller in a bag containing the guppy’s own tank water. But that water’s parameters might differ wildly compared to your tank’s water.

You need to perform a gradual acclimation process, allowing your guppy to adapt to its new environmental conditions. This is to provide the guppies with a safe transition, minimizing the risks of adverse reactions.

How does the Acclimation Process Work for Guppies?

First, you must understand guppies’ environmental requirements so you can set up the tank to the ideal parameters. Here are some of the values to keep an eye on:

  • Water Temperature – The ideal range sits between 72 to 82 °F. Guppies can withstand some temperature variations outside these limits, but not much, not sudden, and certainly not for long periods of time.
  • Water pH and Hardness – Water’s pH and hardness are correlated, with one influencing the other. Guppies prefer a pH between 6.8 to 7.6 and water hardness of 8-12 dGH.
  • Chemical content – Guppies’ water should be free of chlorine, chloramine, ammonia, and nitrates and have a nitrate level of 10-20 ppm max.
  • Mineral content – This point already removes distilled water from the equation. Distilled water is devoid of the essential minerals that guppies require, so don’t use it for your guppies’ tank unless enriched with minerals prior to use.

After you’ve set the water’s parameters, it’s time to acclimate guppies to their new environment. There are 3 primary ways of achieving that:

– The Floating Bag Acclimation Method

The floating bag is probably the most used method only because it’s simple and doesn’t require special equipment or too much knowledge for that matter. There are several simple steps to follow:

  • Keep the bag sealed and let it flow in the tank for half an hour – This is to equalize the differences in temperature between the bag and the tank water. It will allow guppies to accommodate to their new environmental temperatures.
  • Add tank water into the bag – You can do that by cutting a small opening near the bag’s knot and pouring tank water through the opening. Mix water in phases, only adding small quantities at a time until you get 50% tank water and 50% bag water.
  • Allow the bag to sit in to the tank for another 30 minutes – This will allow guppies to acclimate to their new water conditions gradually. You can even keep them in the mixed water for 1-2 hours just to make sure they are comfortable and have acclimated successfully.

If everything looks good, collect the guppies with a fishnet and place them in the tank. Do not spill the bag directly into the tank since you don’t want to use the pet shop water.

– The Bucket Acclimation Method

The Bucket method is more reliable than the previous one, except it requires more work. The procedure goes like this:

  • Prepare an empty bucket – You should use a clean 5-gallon bucket unless you have more fish in need of additional space.
  • Place the fish into the bucket – Be gentle about it to not disturb your fish too much. You should pour the entire bag with the water and the fish into the clean bucket.
  • Begin swapping the water – The process is gradual, as you will remove 25% of the water in the bag and replace it with tank water over time. ‘Over time’ means adding 1 cup of tank water every 5 minutes or so until you replenish the missing 25%.
  • Repeat the process – Once you’ve replenished the lost 25%, remove 50% of the water and repeat the process.
  • Refill the tank – The bucket acclimation process requires tank water to complete, which you won’t be able to use after the process is complete. This means you should refill the tank with freshwater before adding the fish. If you’re using tap water, let it rest for 24 minimum before using it or use a dechlorinator.
  • Move guppies into their new tank – After the acclimation process is complete, you can now move the guppies into their new tank. Monitor your guppies over the next 2-4 hours to make sure they’re comfortable and safe.

This method will take more time and require more work than the floating bag method, but it’s worth it. It prevents bag water from spilling into the main tank for one, preventing unwanted contamination. It also gives your guppies more time to acclimate to their new conditions.

– The Dripping Acclimation Method

This method is, in my opinion, unnecessarily complicated, only fitting for very sensitive saltwater fish. I believe your guppies should do just fine with any of the previous 2 methods. If, however, you want to use the Dripping method, here’s what to do:

  • Rest the fish bag in the tank – This step is identical to the Floating Bag method. Just like in that case, the goal is to equalize the temperatures between the 2 environments.
  • Prepare a bucket and pour the fish in – This is identical to the Bucket method because this is where the acclimation process will take place.
  • Connect the main tank to the bucket via an airline tubbing – The airline system relies on a siphon drip line to deliver precise quantities of water to the bucket. You should tie knots to the tubbing to control the water flow to the desired values. Ideally, you should have 5 to 7 drops of water per second.
  • Double the water and repeat the process – The dripping should continue until the level of the bucket water doubles. Then you empty 50% of the water and redo the entire process until the water level doubles again. At that point, the acclimation process is complete, and guppies are ready for transfer.

Just as with the Bucket method, you need to replenish the missing tank water accordingly.


Your guppies will withstand a variety of environmental changes, but never too sudden. Abrupt shifts in temperature, ammonia, pH, or mineral content can cause guppies to get into shock and die. Best-case scenario – they will experience stress, leading to a weaker immune system, bacterial infections, and diseases.

Take your time to acclimate your guppies to their new habitat properly. After all, with rare exceptions, you will only have to do it once.

Updated: December 9, 2021
Leave a Comment

Your email address will not be published. Required fields are marked *