Tips for packaging fish
If you've never packaged fish to bring to an auction before, the process can be intimidating. But don't worry, it's not hard! Just follow these suggestions to help minimize stress to your fish.
- Don't feed your fish for at least a few days before you bag them. This will help reduce the amount of toxic ammonia that's in the bag with them.
- Net the fish, and put them in a bag filled a third full with clean tank water. Don't put too many fish in a single bag, especially if they are large fish.
- Bag early: Catch the fish the night before and put them in a bag - but don't seal the bag, and put an airstone bubbling slowly in it. Before you drop off your fish, you can change out the water for fresh water and close up the bag.
- Use breather bags. These are expensive, but allow gas exchange, meaning that O2/CO2 are no longer an issue and the only thing you need to be worried about is ammonia.
- Bag with polyfilter or carbon, which help absorb toxins (mostly ammonia) in the bag
- Bag with oxygen - if you have it, inflate the bag with oxygen, which will last longer than regular air.
- Never breath into the bag to inflate it, or you'll get CO2 in it, which can suffocate the fish.
- Never fill the bag more than half full (1/3 full is better), there should be a good amount of air on top of the fish. More air and less water is actually better, since your fish will run out of oxygen in the bag more quickly than ammonia or CO2 will build up in the water.
- Bring your fish to the drop off site in a cooler so they don't get too cold
- Certain corydoras catfish can release a toxin, and poison themselves in the bag. They release it almost immediately after being caught, so you should net them, put them in a container (a yogurt container works well) for 2-5 minutes, then net them out of the container and put them in a bag filled with water from the aquarium they came out of. Discard the water in the container, which will contain the toxin.
- Double bag the cories, loaches, and other fish with sharp spines, because their spines can poke through some bags.
Tips for acclimating new fish
When you get new fish, it's tempting to dump them into the tank right away. But, changes in water chemistry can be lethal! There are a few factors to consider:
* Changes in temperature: changes in temperature of more than a few degrees can shock and rapidly kill fish
* Osmotic shock: changes in water hardness or total dissolved solids are very stressful to fish
* Ammonia and pH: in the bag, CO2 build-up (from the fish breathing) has lowered the pH in the bag. This converts ammonia to the less toxic form NH4 (ammonium). When you open the bag, air rushes in and raises the pH, causing NH4 to convert to NH3. NH3 (ammonia) can cause permanent damage to a fish's gills.
With these in mind, there are a couple approaches that people use to acclimate new fish to their aquariums:
- Scoop and dump: float the bag in the tank for 15-20 minutes so that the temperatures match. (Note: never float a breather bag). Remove the bag from the tank, scoop the fish out with a net, and then dump them into the tank. This approach works well for most cichlids, and larger or hardier fish. This method should not be used with fish that are sensitive to osmostic shock. Never use this method with shrimp.
- Slow acclimation: open the bag and pour in a bit of tank water every 15 minutes. This is the method recommended by almost every pet store I've been to. It would be a good idea to add a tiny bit of dechlorinator as soon as you open the bag (most of these will remove ammonia), but be very careful not to overdose, as dechlorinators can kill fish in high concentrations. Try
adding the dechlorinator to a gallon of water, and then add a half cup of that water to the bag.
- Drip acclimation: Dump the bag of fish into a small container like a 5 gallon bucket, add some dechlorinator (see the tip above to avoid over-dosing), and run a bit of airline tube from the tank to the container. Drip tank water into the container at a rate of 3 drops per second. Continue dripping water for 6 hours (do not cut the time short, new proteins need to be made to allow the fish to adapt to the new water). Don't let the water in the bucket get too cold; it may be good to float the bucket in another tank. It's also a good idea to add an airstone. This method should be used with inverts like shrimp or sensitive fish like wild caught tetras.
Which method is "right"? Of the two largest online fish vendors, Live Aquaria recommends scoop and dump, while Blue Zoo recommends drip acclimation. So, I suspect that for most fish, it really doesn't matter as long as you are careful and understand what kind of fish you are dealing with. If you are not sure which method to use, reach out to the seller and ask for their advice.
Looking for more info? Here's a great video by KJE Aquatics.