Acclimating LARGE Fish


Stingray King
MFK Member
Jul 2, 2005
Spokane, WA
Heres a few things to keep in mind when working with shipping fish over long distances. Acclimation for these fish is a bit different then your usual bag ride home. The key is ammonia poisoning on the fish, and it's important that understand that *Ammonia is more toxic the higher the pH, and the warmer the water*. When a large fish is shipped, it is bound to secrete ammonia into the bag. Fish waste is acidic, and will therefor make the water 'acidic' and drive the pH down. When a larger fish is in a bag for a lengthy amount of time, it uses alot of oxygen. After much of the oxygen has been used, Carbon Dioxide will begin to build up in the bag. If you have ever worked with planted aquariums, you would know that cO2 will drive down the pH. So the longer a large fish is 'breathing' in the bag, the more co2 is present, which means the lower the pH will drop. When a fish is shipped, it is also bound to drop a few degrees in temprature, making ammonia less lethal as well. So after the combination of all these things, the pH has been driven down, the fish is lacking oxygen, and the water has been cooled slightly, all of these things making ammonia less toxic.

Now lets keep these things in mind, and now go over what happens when a fish arrives. Don't ever float the bag, as it restricts oxygen exchange which happens between the bag plastic and the outter atmosphere. It also slowly raises the temprature.

Within 30-60 seconds of the bag being opened, a gas exchange occurs between the waters surface and the water. This is a sudden increase in oxygen, which depletes co2 levels in the bag, thus making the pH make a sudden jump. With this sudden jump in pH, the ammonia immediately becomes more toxic. So you take the advice of many, and begin to drip acclimate. More than likely, your tank's pH is going to be higher than the pH of the bag water (due to fish wastes).. While dripping tank water, you will slowly be raising the pH, which at the same time slowly increase the toxicity of the ammonia. Also drip acclimation will create a slow rise in temprature, which will even further increase the toxicity of the ammonia. So when you think you are doing the proper thing by slowly adjusting your fish to it's new environment, you are actually slowly burning the skin and gills due to ammonia poisoning.

Heres how we acclimate(xaqua), and this have been proven to work for many others. The key is to get the fish out of the bag water, ASAP. We often use scissors to cut open the bag, and immediately (within 3 seconds) squirt an undetermined amount of AmQuel (ammonia detoxifier), as well as NovAqua (water conditioner).. We also use a squirt of these products in the tank in which the fish will be placed, as to best match the 'chemically adjusted water paramaters'. When you swiftly squirt a shot of AmQuel into the bag, it instantly detoxifies the ammonia by chemically binding it with a sulfur based solution. This allows you to net the fish, or strain the water out, in order to calmly place the fish into its new home.

I have read a scientific report which stated fish usually take 6-8 days to acclimate to temprature changes. The key to temprature change in tropical fish is that they never take a sudden DROP in temprature. It is safe to acclimate a fish into a tank that is much warmer than the tank it is coming from. Tropical fish can often take a jump of 3-10 degrees with no problem, however a drop in temprature over 2-3 degrees can prove lethal.

pH/hardness.. This is always an interesting subject, as we hear so many conflicting stories. It is true that FW Stingrays come from the soft waters of the amazon, however they do very well in hard water from what we have found. We acclimate our stingrays from a pH of 7.0, directly to a pH of 7.4-7.6. Many fish can withstand a temprature swing, or a pH swing in the wild. The thing that wild fish cannot tolerate is the presence of Ammonia, Nitrite, and Nitrate. In the wild, fish never have come in contact with any of these 3 'pollutants', however they will experience pH swings and temp changes on a daily basis. It is my belief, as well as the belief of many others, that it is more beneficial to not tamper with the water parameters. It has been proven that it is better to do large frequent water changes, as most fish will adapt to the water paramaters of your tap water source. We change the water 2-3x a day, so we have no time for RO units or chemically adjusting the water, because we believe that 'Stability' is the most important paramaters, rather than matching ideal conditions.

John Kuhns invented the product AmQuel to acclimate wild apistos when they were first being introduced to the hobby many years ago. He developed this 'ammonia' binding chemical to stop ammonia burn from the gas exchange that happens when the bag is first opened. Heres a LINK about the 'Squirt and Dump' acclimation process, as well as more acclimation info..

Another great link...

We also use a product called 'Chemi-Pure' which seems to help alot with acclimation. It helps to keep the fish from going into a state of shock, especially when there is a large different in pH/hardness. When acclimating a rare new fish, it is always a good idea to spend some extra money to 'clarify' your water with some Chemi-pure first. (Works great for Tigrinums.)

Keep in mind this concept is for fish with a LENGTHY bag ride (12+ hours), or large fish which secrete alot of waste.

I hope some people find this knowledge helpful.


cuban jey

"tha movement you bastards"
MFK Member
Aug 11, 2005
Tampa Bay
awesome read miles i thank you and my shipped fish in the future thank you
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Go hard, or go home
MFK Member
May 30, 2005
Miles GREAT stuff dude!

Moderators - i think this would be a good piece for the ARTICLE section of this site as i dont think there is anything there yet!
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Staff member
MFK Member
Jul 23, 2005
Quarantine Tank
wow, gr8 info :) thank you for educating us!


Feeder Fish
MFK Member
Jul 12, 2005
I'm going to print this..... maybe give it as part of a presentaion at one of my aquarium meetings...... of course I'll give you credit.

Thanks for taking the time to share with the rest of us...... I've allways thought that getting them out of the bag was more important that worring over a PH change. I had never added the ammonia detox when I opened the bags but I will start now.

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Blue Tier VIP
MFK Member
Apr 6, 2005
Monster's r us
miles you are like a book of knowledge :clap


Team Rayman
MFK Member
Mar 30, 2005
staten island new york
great read :thumbsup:


MFK Member
May 1, 2005
meriden ,ct
so rather then doing the drip method after adding amquel i should just dump my ray in the tank?

i think rays are the main factor here as everyone makes them seem like they die at the slightest ajustment of ph.....