Many fish cannot be shipped in breather bags, I would not be inclined to ship almost any fish that tends to gulp air from the surface in such a bag. I would not be incline to ship lathe fishor fish with sharp spines. Since I cannot remember receiving anything in a breather bag and have never used thenm to shio, I did tome searching and I found this slightly "poor"information on the Aquarium Co-Cop site.
Thgey suggest using 1/2 inch styro which is not adequate in colder weather, it is a way for me to insure DOAS. Next they did agree with what I wrote above:
Use regular fish bags if you are shipping betta fish that require some air in the bag or fish with spines that may puncture a breather bag. Fill two-thirds of the bag with water and the remaining one-third with air. Seal the first bag with a rubber band, and then slide it upside-down into a second fish bag. Seal the second bag with a rubber band.
There are ways to minimize puncture risk. One way is to wrap the inner bag of two with newspaper. If the inner bag punctures, the paper gets wet and helps by acting to block the leakage some. One can also use 3 mil bags for both inner and outer or even a 4th bag. The thicker the bag material, the harder it becomes to knot and rubber band tightly. More care is need when packing for bigger pointier fish.
Next, the most important thing in a not-breather bag of shipped fish is not the water, it is the air. The absolute minimum I want is 50/50, but I prefer to be closer top 2/3 air.
One of the biggest issues shipping fish is that release ammonia into the water whenever they inhale. According to the science I have read"
These numbers indicate that an oxygen molecule is heavier than a nitrogen molecule. Nevertheless, an O2 molecule has a smaller diameter and thus, a lower volume than an N2 molecule.
So, does ammonia pass out of a breather bag? I could not find out on the Kordon site where I did a search for the word ammonia. They say other gasses can pass in and out, but do not say which ones. But i do know that as the fish travel the ammoniaint the bag water (for normal bags) goes up. Normally this would harm or kill the fish but there are two things that prevent this, when I ship and when anybody ships.
Ammonia exists in two forms in water, Most of it will be ammonium and only a smaller part will be the very toxic ammonia. How much is in th toxic form depends on two factors, The main one is the pH of the water and the secnmd less improtant (but nior irrelevant) is the Temperature. The higher either of these two number are, the more of the ammonia will be in the toxic form. So why don't all fish dioe from ammonia poisoning in transits?
The answer is that the fish also exhale CO2. Co2 in water creates some acid which lower the pH of the water. So while the level of ammonia is increasing so it the CO2 which counteracts the ammonia. I have no idea what happens in this respect in a breather bag.
My number two trick is I add a piece of Poly-Filter to every bag. This absorbs nasties including ammonia and organic waste.
(above line added by edit)
Next, I see it written that in a normal bag with all the air the fish gets tossed about. Well if you have a fish in a breather bag in a box going 50 miles and hour and the driver hits the brakws hard, the fish are not just sitting in place. The get sloshed about asd well. Whe I ship all the bags are padded for the most part. I do not want the fish bumping into hard surfaces.
Kordon says:
n comparison - using the Kordon Breathing Bags allows for no sloshing and no stress. The Breathing Bags are sealed with as little air inside as possible. Ideally only water touches the inner surface of the bag. No air chamber of added oxygen means no slosh-zone and turbulant travel for the fish inside. You can test this by laying a filled Breathing Bag on a flat surface and allowing the fish to settle down. Picking up one edge of the bag - you can roll it until it is totally reversed - upside down - yet the fish inside will not move at all. No sloshing, no jiggling... no stress. Less stress equals less losses or injuries during shipping or transfer of live fish.
So if the FedEx. UPS or other transporter drops the box the fish are going to remain in place in the bag? If you bleive that, I have bridge I can sell you very cheaply.
While I have never shipped in breather bags, I would think these are best used when shipping smaller fish. ANd for sure there are many fish that shuold never be shipped in one.
The kordon site shows 3 bags sizes. "
Item No. 50201 - Breathing Bag™ 7" x 14" (full case is 2000 pieces)
Item No. 50202 - Breathing Bag™ 9" x 16" (full case is 2000 pieces)
Item No. 50203 - Breathing Bag™ 12" x 19" (full case is 1250 pieces)
When I began shipping fish it was small bnristlenose pecos and that soon became 1.5 zebra plecos. The zebras at $1560 each back when were always individualoy bagged. I use 4 inh wide by about 12 inch long (when closed up) bags. No way that would make sence in a bag 7 x 14 inhces. Heavier and bigger than needed. I might ship several guppies, tetras etc. in a breather that size but not a single smaller pleco.
Finally, I shipped a bag of 6 bristlenose plecos in traditional bags. I am 35 miles NNE of New York City and the box was sent to Alaska in early April via USPS Express. The box was dropped at the PO early afternoon Monday and got delayed and it did not arrive in Alaska unti; Friday late afternoon. All the fish arrived alive and OK.
I am completely OK shipping using traditional as opposed to breather bags. However, I am not saying that one should never use such bags, They make sense for some folks for specific applications. But that is like evrything else in the hobby, very few universals and plenty of different ways to do things that are perfectly fine in some cases and not in others.
I do wonder about one thing. Nobody is perfect and sometime bags can tear or have a defect. I assume not 100% of breather bags will experience this now and then. But with just a single bag, wont this mean dead fish?
(edited for line added by edit noted above and for typos and spelling)