How Do You Introduce Fish to your Tank?

I think we have to acclimate ourselves in this hobby, and it comes with a slow drip of learning. Prevention matters, and I make sure I know what I am getting and prepare the tanks in advance. If I were to get a coastal livebearer, I would harden the water in my tank. If I am getting a Central African fish, I'll keep it as it comes from the tap here - soft. I'll have the temperature of the tank at the levels the fish would meet in nature. The tank has to be ready.

I equalize temperatures between the bag and the tank. I'm in Canada, and for quite a few months, it's cold. Fish usually arrive a little chilled. When I bought a lot of pet store fish, we semi-jokingly called half the year Ich season. If that parasite is present, thermal shock helps it out greatly. It loves a temperature shocked fish. It likes a temp that drops best, and stores tend to run around 24. So 24, in transit drop to 20, and then a quick return to 24 is in order.

I want the fish out of the ammonia and stress/fear hormone laced waters as quickly as possible, and I want none of that water to get into the tank.

We're looking at the following factors:

temperature differences;
water chemistry issues, in terms of mineral content and pH;
ammonia and hormonal build up;
often overloaded bags )too many fish, too little water);
parasites, viruses and pathogens in fish store water;
fish that may be unhealthy from the get go;
the need for speed.

Drip acclimation isn't going to go away. It'll still have some righteous supporters, as well as reasonable ones. It's an attempt to do the right thing. I don't agree with it, but most fish do survive it. Last week, on FB, I was told I was a cruel idiot who clearly had never kept fish because I suggested there were issues with drip acclimation. That attitude either way in the debate isn't helpful, but we can work past it.

Essjay said:

I do the same as CaptianBarnicles, float to equalise the temperature then fish straight in the tank. But no store water.


The reason the adding water over time can be deadly to fish which have been shipped is ammonia. While they've been in transit they've been excreting ammonia and breathing. They breathe out CO2 like we do; this builds up in the water and lowers the pH. Ammonia is less toxic at low pH, so the fish are safe. Then they are delivered, the fish keeper opens the bag and that dissolved CO2 gasses off - and the pH rises making the ammonia more toxic. The fish now sit in this toxic ammonia for however long the fish keeper spends adding water to the bag.

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Yes! this was the most interesting part of the article. I had no idea this would happen, but will definitely use some version of the cut dump plop (or whatever) method going forward. BTW - for temperature acclimation, another article by David Bogert apparently dispels the idea that most fish can't take temperature swings. I'll find it and put it here- taking a break from work now and don't have time LOL.

I have a saying I developed in this hobby years ago: You can lead a fishkeeper to water, but you can't make them think.

There is actually well established science behind most of what we do in the hobby.
But you will rarely find it on social media where information goes to die. I spend more time using Google Scholar https://scholar.google.com/ rather than plain Google Search when it comes to issues involved with keeping fish.

I used to work with a good friend who imported fish for a home based business. She would pick up from a transshipper in NYC on Sundays soon after they had landed via plane. For her it was an 8 hour journey, so I began picking up for her and meeting her halfway between use. For this I was able to buy things at import prices.

When she first began importing she acclimated and she typically had losses of 25% or more. Then she was told by folks with more experience in importing that she should Plop and Drop. So she began doing that. The results was her losses dropped from over 25% to under 10%.

I use to acclimate fish until I began reading research papers. No matter what the purpose of the research, it almost always involved acclimating the fish before the experiment. The periods involved almost always ranged from 2 to 4 weeks. Why would Ph.D. scientists bother to do this if they could acclimate fish in a matter of hours or a couple of days? Never once did I read about a drip acclimation being done.

There is a very good reason for this. Acclimation usually involves biological changes occurring inside a fish. These can often take two weeks or more to show up. So we are fooling ourselves if we believe we can acclimate fish in a matter of hours or even a few days in most cases.

The secret to not killing fish because they get put into radically different parameters than we have in our tanks is simple, do not get that species. The alternative is to change your water parameters. Doing this in a consistent and stable way is not so easy. It is much harder to lower pH and soften water than it is to raise these things. I know as I have done/do both. To keep my Altum angels I need both an RO/DI unit to make pure water and then I use alder cones and Catappa leaves to help maintain the parameters, When I need more help, I use muriatic acid to drop the pH. Like I said, it is not so easy to change parameters

edited for spelling and typos

emeraldking said:

How Do You Introduce Fish to your Tank?​

I'll keep them in a separate tank first for a number of days before they'll enter their final tank.

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Thanks, emeraldking- I've seen a lot of reference to a "quarantine" tank and I think that's a great idea- especially for fish from big box stores, but if I bring another tank home my wife will shoot me.

TwoTankAmin said:

I have a saying I developed in this hobby years ago: You can lead a fishkeeper to water, but you can't make them think.

There is actually well established science behind most of what we do in the hobby.
But you will rarely find it on social media where information goes to die. I spend more time using Google Scholar https://scholar.google.com/ rather than plain Google Search when it comes to issues involved with keeping fish.

I used to work with a good friend who imported fish for a home based business. She would piick up from a transhipper in NYC on Sundays soon after they had landed via plane. For her it was an 8 hour journey, so I began picking up for here and meeting here halfway between use. For this I was able to buy things at import prices.

When she first began importing she acclimated and she typically had losses of 25% or more. Then she was told by folks with more experience in importing that she should Plop and Drop. So she began doing that. The results was her losses dropped from over 25% to under 10%.

I use to acclimate fish until I began reading research papers. No matter what the purpose of the research, it almost always involved acclimating the fish before the experiment. The periods involved almost always ranged from 2 to 4 weeks. Why would Ph.D. scientists bother to do this if they could acclimate fish in a matter of hours or a couple of days? Never once did I read about a drip acclimation being done.

There is a very good reason for this. Acclimation usually involves biological changes occurring inside a fish. These can often take two weeks or more to show up. So we are fooling ourselves if we believe we can acclimate fish in a matter of hours or even a few days in most cases.

The secret to not killing fish because they get put into radically different parameters than we have in our tanks is simple, do not get that species. The alternative is to change your water parameters. Doing this in a consistent and stable way is not so easy. It is much harder to lower pH and soften water than it is to raise these things. I know as I have done/do both. To keep my Altum angels I need both an RO/Di unit to make pure water and then I use alder cones and Catappa leaves to help maintain the parameters, When I need more help, I use muriatic acid to drop the pH. Like I said, it is not so easy to change parameters

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TwoTank admin- I love finding guys like you who have already read the books and research papers These articles by David Bogert have been really eye opening- I'm trying not to become a fanboy, but it really seems like he is stating facts (except where he calls out opinion) based on research or, in some cases, tests he performed himself. That provides a level of comfort I can't find with Mr. Random "you are going to kill your fish!!!" guy.

MuddyWaters said:

Thanks, emeraldking- I've seen a lot of reference to a "quarantine" tank and I think that's a great idea- especially for fish from big box stores, but if I bring another tank home my wife will shoot me.

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Well, a bucket works as well...

emeraldking said:

Well, a bucket works as well...

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Oh.....hmmm I never thought of that LOL

MuddyWaters said:

Oh.....hmmm I never thought of that LOL

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You need to be creative when the missis keeps an eye on you...
And you know what...? They see everything...! So, a bucket comes cheap and isn't that obvious... And most important...it works!

MuddyWaters said:

Thanks, emeraldking- I've seen a lot of reference to a "quarantine" tank and I think that's a great idea- especially for fish from big box stores, but if I bring another tank home my wife will shoot me.

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I've purchased fish from a LFS and had same results as far as deaths from a big box store. There's another LFS that I've had a much better expericne with low death rates after purchase. Guess where I get most of my fish now? Yeah, I have to drive a bit further but it's worth.

I usually float the bags for new fish to acclimate to temps but from the posts here I'm thinking I should just pop them in the tank right away from now on.

I keep 4-5 dishpans from the Dollar Store… they were thinner and cheap, and a little flimsy to carry if close to full, as my aquarium use only tubs, and they work great with my process above

Beware of ich if the tank is cooler than the bag water. I have never had trouble putting fish into warmer water. One paper I read suggested that a 3 degree celsius drop was the outer limit for fish health though. Going into colder water quickly can be a problem.

So if you live in an inferno and the water gets very warm in the car, putting the fish into a much cooler tank can be a killer. If you live in a freezer, as I do, putting fish into a warmer tank is good.

I've had a remarkably similar experience with importing when I read @TwoTankAmin . More than once, airlines have left clearly marked fish shipments on sub zero tarmacs, and when those arrive, they go right into warmer water, at the temps they'll be kept at. If you warm the tank for them, then the temps will drop when you stop, and that's a stressful roller coaster. But speed speed speed is the road to safe handling of shipped fish. Plop and warm also has its place. I have kept fish for years that I would have sworn were dead when they arrived. With speed, they revived, and went on the thrive for generations here.

When a box of fish arrives, once you open it, you don't check your phone or have a cup of tea til everything in it is safe.

A fish keeper’s nightmare, a doa, I certainly wouldn’t float this bag, with one dead fish in it, there my goal was to get the live fish out as fast as possible… I used my method listed above… not sure if they will all live or not, but going on day three for ones live in the bag… the live ones we’re breathing rapidly… not sure if lack of oxygen, or ammonia in the bag, were likely issues

Most folks here know me as the nut who reads and posts research papers. Science is the best information at the time. It may be revised, changed or even discarded when newer science replaces/changes it. That is the nature of the scientific method. Also, many decades ago I was a psych major and had to learn to do research for experimental psych class.

Anyway, some years ago I got curious about acclimation and went looking for any research on it. The only thing I could find dealt with temperature And it was mostly concerned with discovering the points at which the water was hot or cold enough to kill fish. They examined how the behavior of fish changed as the fatal temperatures were reached.

I was not happy to be reading about fish being killed as the whole point of acclimation is the opposite. But one study really impressed me and has stayed with me over the years. One group of researchers was actually interested in learning about what one should do when one notices fish behaving in a way that indicates they would soon be dying as they were at or very near the fatal levels.

What they discovered was that to save the fish what one needed to do was, as quickly as possible, get the fish into water within the normal temperature range for the fish. The important things was speed, and this meant no acclimation. They found this was what brought fish back from the brink. It is also what stopped me from doing temperature acclimation. I had already abandoned acclimating for the other water parameters.

I also have gotten a bit of reinforcement of the effectiveness of the above. I had a tank which held a pair of adult discus, a small school of rummy nose tetras and a group of 6 Hypancistrus L450 I was growing out to spawn. Working in the space where that tank was I discovered a heater malfunction (it stuck full on) had raised the water temp. to 104F (40C) the discus were both dead, the rummy nose were all balls of mush, but all of the L450s were hunkered down in caves on the bottom of the tank breathing heavily.

I did two things as fast as I could. One was to remove the dead fish and the next was to do a huge water change to get the temp. down into the low 80s ASAP. This was accomplished in about 15 minutes. All of the plecos lived and about 6 weeks later they started to spawn. I have little doubt that had I not discovered the tank when I did that the plecos would likely have died as well. I am certain that changing the temp as I did also saved them as well.

A few years back I was vending at a weekend event in late March in the state of CT. I arrive Thursdays to set up in the evening, but many vendors do not arrive until Friday morning. That year there was a temperature drop and it snowed over nigh and was below freezing all day Friday.

One of the vendors to arrive that morning was a discus outfit. They had a van with a built in "yank" typr container and a generator to make electricity for filtration and heating. The generator had died along the way and the fish were in very cold water. They were very concerned about losing the fish. i explained to one of the owners about the research I knew re temperature and saving fish. I politely suggested they skip any acclimation and plop them into the proper temp. water ASAP.

I was told they were discus experts and knew what to do and proceeded to acclimate their fish slowly. When they were done they had suffered a lot of losses. They were not real happy.

As I am inclined to say: "You can lead a fish keeper to water, but you can't make them think."

Thanks for sharing that, no more floating for me then!

TwoTankAmin said:

I was told they were discus experts and knew what to do and proceeded to acclimate their fish slowly. When they were done they had suffered a lot of losses. They were not real happy.

As I am inclined to say: "You can lead a fish keeper to water, but you can't make them think."

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Maybe next time they'll try your method.