By: Absolutely Fish Staff
For Freshwater Fish:
Open the bag by pulling on the loose end to pop off the rubber band. While still floating the bag, hold it upright and roll down the edges slightly. This is to make it stay upright by itself. You can hook the edge of the bag on the corner of the aquarium if this helps to keep it upright.
Check to make sure the top of the bag is staying open so the fish can get air.
Now add one cup of your aquarium water to the bag. Repeat this by adding one cup of aquarium water every five (5) minutes for the next thirty to forty-five (30 – 45) minutes, six to nine (6-9) times. This will ensure that the fish get used to their new water environment.
If you find that the bag gets too full before finishing, take some water out and discard it – but not into your tank!
After this, you are ready to introduce your fish into the tank. If you have aggressive fish already in your tank, it may be wise to feed them first, and then turn off the aquarium light until tomorrow. Gently lift the fish out of the bag with a net or wet hands and place them in your tank.
Before discarding the bag, make sure the fish appear to be adjusting well. If they sink to the bottom like rocks and don’t move, carefully put them back in the bag and repeat the above process for a while longer and try again. Watch your tank carefully to be sure the new arrivals are not being harassed by the older tank mates. If they are, you may need to separate them with a tank divider for a few days. If you follow this advice, you will cut down on unnecessary fish losses, and get more enjoyment from the hobby!
*The Drip Method described for marine fish can be used for any freshwater fish, and is the preferred method for large or delicate ones.
For Marine Fish:
The safest way to introduce new marine fish to your tank is to use the “Drip Method*.
To use this method, you need a clean bucket, a five (5) gallon pail is perfect, and a drip-line. You can make your own drip-line with some airline tubing, some 3/16″ rigid tubing, and a plastic air valve, or you can purchase one from your dealer already made (ask for details).
As soon as you get your new fish home, float the closed bag in your tank for fifteen (15) minutes to make sure the bag water temperature is the same as your tank. After this time, open the bag and gently pour the water and fish into your bucket. Hang the drip-line by inserting the U-shaped rigid tube into the aquarium.
Lightly suck on the other end-with the air valve to start a siphon. Quickly lower the line into the bucket and observe the flow rate of the siphon. Adjust the flow using the air valve so that there is a light stream coming out (open valve just past a drip). Let the tank water mix with the bucket water in this manner for one (1) hour.
You should remove and discard excess water whenever it is three inches above the fish. This will ensure that they get enough oxygen, as they are always close to the surface.
After one (1) hour is up, gently remove the fish with a small container (Tupperware or the like), or wet hands (if the fish is not venomous or dangerous!) and place them into the aquarium.
It is good practice to feed the old tank mates while dripping the new fish, then move the tank decorations around (you can always put them back the way you like after a couple of days). This will disorient the old fish, and they will be less likely to defend their territories against the newcomers. If they still harass the new arrivals, turn the light off until tomorrow or separate the new ones with a clear tank divider for a couple of days.
Don’t try to feed the new fish the first day, and don’t get too alarmed if they don’t eat for several days. If you have any concerns, ask your sales person. Remember, marine fish are sensitive to environmental changes – give them every chance to thrive.