Warning- this is a pretty long post.
I am happy the fish in this thread appear to be doing great. However, I wonder if you are aware of the chemistry involved with shipping fish and why some of us who get most of our fish shipped in deal with unbagging and why we do the plop and drop.
Depending on how many fish and their size and how many are in a bag combined with how long they have been there until we get them and why getting the fish out ASAP with no acclimation is the preferred method by many folks.
1. If you read research into how long it takes fish to adapt to changed parameters, you will see it can take one or two weeks for them to adjust in terms of the physiological changes they undergo? One of the things that I learned realy on in reading presearch papers was how long the researechers would acclimate fish before they began an experiment. It is often 2 weeks and sometime a bit more. This wait is not because they are lazy about getting started.
2. When the research involves how a given species deals with parameter changes and may or may not adapt to them, these again show that the time to become "acclimated" is measured in many days to weeks not minutes or hours. We are talking biological type adaptions. The study below is a good example:
Gill membrane remodeling with soft-water acclimation in zebrafish (Danio rerio)
Paul M. Craig, Chris M. Wood, and Grant B. McClelland
Physiological Genomics 2007 30:1, 53-60
https://journals.physiology.org/doi/full/10.1152/physiolgenomics.00195.2006
Abstract
Little is known regarding the ionoregulatory abilities of zebrafish exposed to soft water despite the popularity of this model organism for physiology and aquatic toxicology. We examined genomic and nongenomic changes to gills of zebrafish as they were progressively acclimated from moderately hard freshwater to typical soft water over 7 days and held in soft water for another 7 days. Gills were sampled daily and mRNA expression levels of gill Na+-K+-ATPase (NKA) α1a subunit, epithelium calcium channel (ECaC), carbonic anhydrase-1 and 2 (CA-1, CA-2), Na+/H+ exchanger (NHE-2), V-type proton (H+)-ATPase, and copper transport protein (CTR-1) were quantified by real-time PCR. Changes in enzyme activities of gill NKA were determined and protein levels of NKA and ECaC were quantified by Western blotting. Levels of mRNA for ECaC increased fourfold after
day 6, with an associated increase in ECaC protein levels after 1 wk in soft water. CA-1 and CA-2 exhibited a 1.5- and 6-fold increase in gene expression on
days 6 and
5, respectively. Likewise, there was a fivefold increase in NHE-2 expression after
day 6. Surprisingly, CTR-1 mRNA showed a large transient increase (over threefold) on
day 6, while H+-ATPase mRNA did not change. These data demonstrate a high degree of phenotypic plasticity in zebrafish gills exposed to an ion-poor environment. This not only enhances our understanding of ionoregulatory processes in fish but also highlights the need for proper experimental design for studies involving preacclimation to soft water (e.g., metal toxicity).
As you can see, some adaptive changes take time to happen in the fish.
3. What happens in a bag between the time the fish are put in and are then in transit for a day or more depending on shipping method. Sometimes a box is delayed and the fish are in the bags for more time than expected.
The bag water starts off fresh and clean. The pH and TDS are proper for the fish, or pretty close to it. Then the fish breath. With each "exhale" they are excreting ammonia and CO2. The acid from the CO2 acts to lower the pH of the water. So even as the ammonia level starts to rise, the pH is starting to drop and this helps to keep much or all of the ammonia being created in the form of ammonium. Even if purged before bagging, the fish may still poop especially the longer they are in the bag.
Whe we then open the bag what happens is the excess CO2 comes out with the result being the ammonium starts to turn back into NH3. So the more and bigger the fish are in the bag and the longer they have been there, the greater the risk.
4. Next, "Yes, freshwater fish urinate constantly to get rid of excess water and ammonia, producing large amounts of very dilute urine through their kidneys and vent, as their bodies constantly absorb water from the environment. Since they don't need to conserve water like marine fish, they pee frequently, effectively flushing out metabolic waste like ammonia (a nitrogen compound) and keeping their internal salt balance in check, often releasing waste through their gills too." So, the bag water is getting further degraded.
The bag water can be on the nasty side and it is often good idea to get the fish out of it ASAP. Of course the size, number and species of fish involved and the transit time matters in this.
I learned to stop trying to acclimate new fish shipped to me from Rachel O;Leary, aka msjinkzd. She was importing fish and buying them wholesale regularly. Early on she was loosing a fair number soon after receiving them and getting them into her tanks. She was doing what we call traditional acclimation. When she started asking around, she was told to stop acclimating and to start plopping and dropping. Her losses were cut tp about 10% max. and sometimes there were almost none at all.
The result of this and the papers I read convinced me to change what I was doing. A number of years ago I wanted to get some very rare and pricey plecos. In order to buy 15 each of two pleco species I also had to buy 100 zebra plecos. They were shipped to me from CA and I am in NY. When the box arrived there were two bags in it. One held 15 of one of the two fish I really wanted and the other held all 100 zebras (is was actually 999 as the seller miscounted). The second species had been sold out from under me and I eventually got them years later from another source.
Dealing with the 15 was easy. They were plopped and dropped into their new tank right away. But the zebras needed to go into several tanks. There was a single DOA in the bag and the process of removing the rest by putting them into different buckets of tap water (I have a well and my tap and tanks tend to have almost identical parameters.) In spite of my working as fast as I could, I still lost another 3 zebras. But the rest were all OK as they were put intp clean water without any acclimation.
The bag with the zebras was huge, But it had about 2-3 inches of water and the rest was air. I would guess the ratio of water to air was about 1::15. What I can say is that for the past 20 years I have gotten about 95% of my fish shipped to me. When they have been packed properly and arrived within 1-3 days, losses were very minimal or 0. And I was often buying imported fish in quantity working with Rachel.
Rachel imported using a transhipper in NYC near the airport. I would drive there and pick up her order pay for it and then I would meet her halfway to her home. I was given a tour of the transshipper facility at one point. I saw their water storage system in the basement and got to watch them opening the bags of fish which were in big numbers. They woould open the bags dump the fish into a container of clean water and then rebag them in the smaller numbers going to each buyer. They then reboxed them for each buyer to pick up. We are talking about a few 1,000 fish of assorted species being plopped and dropped at the transshipper's facility.
The advantage of working with Rachel was that, over time, she had learned which original sellers it was best to get specific aspecies from as they were the most healthy and had the fewest DOAs. She had to learn this the hard way and that meant I did not have to do this. The transshipper offered fish from multiple countries and companies and I benefitted from her knowledge.
All of the above is why I have not tried to acclimate newly arrived fish for two decades now. Of course this is how I choose to do things which does not mean other methods cannot work, I just see the risk in using other methods one I prefer not to take. This is my choice.
