How to Acclimate New Fish to Your Tank Without

By Eddie Waithaka @aquariawise

How to Long to Acclimate Fish

Whether a new or versed aquarist, once a while, you will bring a new guy home and introduce him to your aquarium. AND while acclimating might seem pretty easy, it does get very stressful for the fish. Especially if you purchased the fish online and had it shipped to your address.

Reason being, most of the time your fish will be shipped to you by USPS, FedEx or UPS, meaning it’s going to be in the shipping bag longer than fish you purchase from your local pet store and drive home.

However, it’s important to realize that the acclimation process is Not entirely a big deal, rest you get scared by blogs that make it seem like rocket science.

I know there is the chance you’ll lose a fish once a while, but overall Most of your new guys should be fine.

Unless something is scandalously wrong, then you may have to look beyond the acclimation process.

Still, it’s not rare to get hobbyists who want to understand the proper way to acclimate new fish to their aquaria. And there are a bunch of different ways to do this. From the floating bag method to using a bucket and even drip acclimation. It all depends on your situation.

And since this subject is essential to the survival of your new fish, this article we’ll teach you the two most effective acclimation methods with step by step how to guides, plus look at the proper way to acclimate shipped fish into a new tank.

Lastly, ill leave a few important tips particularly helpful to new aquarists.

The Two Most Effective Fish Acclimation Methods

Regularly, arguments ensure within aquarist quarters on which acclimation method is best, and rightfully so.

What’s important to note though, is that no acclimation method is wrong; at least not necessarily. Just that some methods are less desirable than others; again depending on the situation.

So, let’s turn our focus to the two most common and considerably safe acclimation methods individually.

Acclimating Fish with The Drip Method

Some aquarists swear by the drip acclimation method. They argue that the method is the most effective since you acclimate your fish slowly.

This way you won’t cause unnecessary stress to the fish.

Now, in order to acclimate with the drip method, you will need to have a drip acclimation kit which is fairly cheap. It should not cost you more than $6.

Basically, the kit is just a flexible tubing and maybe a few attaching pieces.

In fact, if you are barely resourceful you can Quickly and Easily DIY your own drip acclimation kit.

The Quickest 6 Steps Drip Acclimation Guide

Step #1— Float The Shipping Bag (plus the fish) in Your Aquarium

Once you’ve gathered all supplies, you’ll first want to float the fish in your aquarium while still inside the shipping bag for 20 to 30 minutes. Simply dip the bag in the tank after you make sure it’s intact.

If your bag is torn or your fish dint come inside a plastic bag, maybe you got it from a friend who is relocating, you can use any other appropriate plastic bag as long as its airtight and will float in your tank.

This floating process is called temperature acclimation.

The reason we temperature acclimate is to ensure your fish doesn’t succumb to thermal shock. However, find out the temperature preference of your fish before placing him in the aquarium just so your tank is not too warm or cold.

In case your fish tank does get too warm especially in summer, consider getting a chiller (can be quite pricey) and if too cold an aquarium heater.

Step #2— Fill a Bucket Just Under Halfway with Aquarium Water

Fill a 5-gallon bucket with clean aquarium water just under halfway full. Basically, you can fill the bucket any way you know best, but most people will just use any clean plastic container -whichever size.

You may need to acclimate your fish to the bucket water temperature before the next step, but it’s not absolutely necessary. The temperature change in the split second you take to fill the bucket is most likely not enough for any significant difference.

Step #3— Transfer Your Fish into The Bucket

Now its time to take your fish out of the shipping bag. Gently lift the bag and pour the content including the fish into the bucket.

Make sure when you pour the content inside the bucket, you tilt the bag in such a way that your fish is fully submerged.

Also, confirm there is enough water in the container for the fish to be upright and it’s NOT flapping around on its side.

Step #4— Siphoning

Place your siphoning tube from the kit with one end in your aquarium down to the bucket. Ideally, you want a drip rate of 3 to 5 drops per second.

You should also tie a few loose knots in the tubing to regulate the flow of air and water. If gravity fails you and the water doesn’t flow automatically, it’s OK to start the flow by gently sucking on the tube end closest to your bucket.

Once the tubing is properly set, leave the process to run till your bucket water doubles.

Step #5 — Discard Half The Water

Once the water in the bucket doubles, briefly stop the siphoning and discard half the water in your bucket. You may need to use a cup to make sure you don’t leave your fish in the drain.

After the bucket is half full, repeat the siphoning till the water in the bucket double again. Pretty much the same you did the first time.

Step #6 — Transfer Your Fish to the Aquarium

Using a bag, scoop out your fish and pour the content of the bag into the main aquarium. Ideally, this should be the aquarium you used to acclimate the fish. In case you have more than one tank, each will have its own ecosystem, so try not to mix up the content.

Also, some freshwater species like clams don’t do well if exposed to air, so take extra caution when transferring them to your aquarium.

Acclimating Fish With The Floating Method

The floating method is an easy, pretty straight forward acclimation method. It’s best for beginning aquarist or when acclimating fish that is not fussy about water chemistry.

However, the method is not very ideal for most reef tank inhabitants because most are complex ecosystems with fish species that require very specific acclimation.

But when your fish is a freshwater species that was bought online and shipped to you it might be the better option.

The Easy 6 Steps Floating Acclimation Guide

Step #1 — Switch Off Your Aquarium Lights

Bright light can cause unnecessary stress or trauma to your fish especially with sudden exposure.

So, before you unpack your carrier box, Shut Off your aquarium lights plus dim any bright lights in the room. Reducing the light is also imperative when floating your fish in an aquarium with aggressive species.

Of course, you can’t completely switch off the lights when working in a poorly lit room, for this reason, consider dimmable lights for such instances if you don’t have them already.

Step #2 — Float the Sealed Bag in The Aquarium

In any acclimation method, floating the bag serves the same purpose. To temperature acclimate your fish to the aquarium. Mostly it’s to keep the fish from thermal shock but also maintain a high level of dissolved oxygen.

A normal temperature acclimation process should not take more than 30 minutes.

Step #3 — Open and Roll The Top Edge of The Bag

After floating the bag for a while, open the bag and roll the top edge to create an air pocket. Unlike a coral bag that you would just cut open, take your time to remove the rubber band or metal clip.

Carefully opening the bag is important because the next step will require the bag to be more or less intact. It also helps the bag to remain sturdy enough and not collapse on the fish.

Make sure your bag will float on the surface of the water. For heavy pieces that will submerge the bag, use a plastic bowl or specimen container.

Step #4 — Add Water to The Shipping Bag

After a few minutes of floating the bag, start introducing tank water into the bag.

Start with half a cup of water and repeat the step every five minutes until the shipping bag is full. This will further help stabilize the temperature and also equalize the chemical differences in the water.

If your bag is flowing around too much, place an algae magnet inside the bag to secure it to the side of the aquarium.

Step #5 — Discard Half The Water from The Bag

Once the bag is full, lift it from the aquarium and discard half the water.

Float the bag in the aquarium again and repeat the filling process for the second time.

Step #6 — Transfer Your Fish to the Aquarium

It’s now time to introduce your fish into the aquarium. It’s best if you don’t introduce any water from the bag into your system.

Thus, use your hands or a net to gently put your fish into the aquarium from the shipping bag. Then remove the filled shipping bag from the aquarium and discard the water.

Acclimate Saltwater Fish Vs Freshwater Fish

The purpose of acclimation is simple: the water that a fish comes from or is packaged in has a different temperature, pH and salinity parameters than your aquarium water.

Unfortunately, most new fish thrust into new environments risk dying from pH if not temperature shock; unknown to their owners. Moreover, while almost all acclimation methods will adapt new fish to the aquarium temperature, few pay due regard to the pH.

Most people will only float the bag in the tank to equalize the temperature and then dump the fish, water and all into their tanks.

Probably because ideally, there is no normal pH that applies to all fish. Think of it as a preference!

Fish originate from ponds, rivers, streams, lakes or oceans, so they prefer different conditions.

Saltwater fish prefer an alkaline pH of 8.0 or above whereas freshwater fish will thrive in a range lower than that, somewhere between 5.5 and 7.5 depending on the species.

So, make sure your saltwater aquarium pH is somewhere in the region of 8.0 and above. In a freshwater aquarium, a water pH around 6.0 is good enough.

A better approach would be to research the pH preferred by your new fish coz some are too sensitive. A difference even as low as .5 might send your fish into pH shock.

An aquarium test kit (see recommended product) will especially come in handy to help you check your water parameter before adding your new fish.

Acclimate Saltwater Fish

To acclimate saltwater fish you can use either of the two acclimation methods.

The floating method is perfect for inexperienced aquarist or when you need to acclimate basic ornamental fish. The method is fairly basic and the results are akin to the those of drip acclimation.

The drip method is considered more advanced and is geared towards sensitive inhabitants such as corals, shrimp, sea star and wrasses. Plus you will need more supplies than with the floating method.

Another thing you should consider is using a quarantine tank to hold the new fish for two to three weeks.

Merely dumping new fish together with the pet store water into your aquarium is a poor way to acclimate which is likely to transfer undetected diseases and parasites to your aquarium.

Acclimating Shipped Fish

The way to acclimate fish that has been shipped to you may be a little different than fish you buy from your local pet store.

First, you will want to track your shipment closely to make sure you are home when the fish is delivered.

It’s already hard enough that the little guy has been in that shipping bag for a while. So, you do not want to prolong the misery by letting it stay in the mail for hours.

Plus you don’t want the mailbox out in the sun or cold for too long. Fish are very sensitive to temperature and leaving your box outside will only add to the shipping stresses.

Once you receive and open your bag, make sure the fish is alive and in good condition. If for some reason he is not, take a picture or video of him inside the unopened shipping bag and send it to the seller.

Most times, sellers will have a Live Arrival Guarantee only, meaning they can’t be responsible for the way you acclimate your fish. Which would also mean it’ll be hard to distinguish between a dead arrival from an improperly acclimated fish without the photo or video evidence.

Later, float your fish in the aquarium to temperature acclimate the water in the bag to that of your fish tank. Do this for 20 to 30 minutes.

It’s better to keep the aquarium lights off especially when you have aggressive species in the tank. In fact, keep the lights off for at least 24 hours anytime you bring new fish to your aquarium.

The method you opt for after this will entirely depend on you. I would, however, recommend you immediately place your fish into the tank either by hand or using a net. You could even use the drip method, but I highly discourage this for reasons I’ll mention in a minute.

A preferable chop is to use your hands, especially when transferring fish with flowy delicate fins. This way you will be more gentle with the fish as opposed to when using a net.

Under no circumstance should you mix the shipping water with your aquarium water because the fish has been in that bag excreating waste and CO2 for the past upwards of 12hours.

Now back to why drip or bucket fish acclimation is undesirable for shipped fish.

First, you need to understand what goes on with the water chemistry in the shipping bag.

Your fish will most likely be packaged with a little bit of water with the rest filled up with pure oxygen. During transit, your fish will use up the oxygen replacing it with CO2 and also excrete Ammonia.

Thus, there will be build up of both CO2 and Ammonia, which should normally be a bad thing. But the CO2 will keep the water pH low meaning Ammonia, the undesirable and the conveniently more toxic element will be less potent.

But once your fish is home and you open the shipping bag, the CO2 will escape into the atmosphere and drive the pH way up making the Ammonia extremely toxic to the fish.

So, for this reason, if you try to acclimate the fish to your water via drip acclimation or any other similar method, you’ll do more harm to the fish than good.

Which will expose your fish to potentially irreversible gill damage either from a pH spike or ammonia spike or both.

You may decide to add a neutralizer once you open the bag, but that will only address the Ammonia issue and not the pH spike.

Hence, it’s better to steer clear of the drip method while acclimating shipped fish. And don’t open the shipping bag until you are physically ready to acclimate.

If you must use a drip or bucket to acclimate, it’s exceptionally important you detoxify the water as soon as you open the shipping bag. Which means you need to put at least a drop of water conditioner.

And if you’ll drip acclimate over a prolonged duration, I would recommend using a piece of poly-filter as well.

8 Helpful Fish Acclimating Tips Every Beginner Should Learn

  1. It is a good practice to detoxify shipped fish. If you don’t you will not only burn your fish scales and skin but also their gill meaning they’ll have a very hard time breathing. Not only that, Ammonia will compromise their slime coat and make your fish more susceptible to bacterial infections and disease.
  2. A slow, careful acclimatization process will give your new fish the best chance for survival in your tank, although it will not protect your other fish from any diseases or parasites that the new fish may be carrying.
  3. If possible, avoid transferring your fish using a net, particularly when acclimating fish with delicate flowy fins rest it gets stuck in the netting. It is better to use a bag to transfer when drip acclimating or your hands if using the floating method.
  4. Try not to introduce any of the pet store water into your system. The thinking here is that some stores treat their tanks with copper-based medication to inhibit fish related diseases. But then the medications are deadly to coral and inverts if you have them in your aquarium.
  5. Use an aquarium divider to contain any tank bully giving the new fish a hard time. Contain him for several hours till the newcomer adjusts to the surroundings. That said, never place the new arrival in the floating basket because it needs to get familiar with your aquarium setting.
  6. A plastic lighting grid, available in your local hardware store can also be used to cut down the width of your aquarium. The grid will section off a small portion of the aquarium to separate territorial or aggressive fish from the newest tank mate. Remove the grid once the new fish adjusts to the aquarium.
  7. Always determine your fish preferred pH before introducing him to your aquarium. There is nothing less appealing than your fish surviving thermal shock only to be killed by inappropriate aquarium pH. With a glass test tube, color card, pH test solution and basic chemistry knowledge, you can test your aquarium pH in less than five minutes.
  8. It is essential to quarantine new aquarium fish for one or two weeks. The fish may carry diseases and parasites such as ich and velvet. Also, although there are copper-based medicines that can treat aquarium fish, the medicines are mostly toxic to inverts and coral which may cause issues in reef tanks.

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Have fun with your fish, and hope you’ll enjoy fish keeping.

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