By Richard Gilliland
Removing dead fish is a very simple process actually, but you have to be sure the fish is really dead. Dead fish will temporarily sink to the bottom of the aquarium, but then soon enough, they will begin floating in the tank in the infamous belly-up position. This is the time when the fish will begin releasing toxins into the water. When you see a fish in this manner, remove it as soon as possible. It is not a good idea, however, to actually handle dead fish. You must use small nets or gloves to remove the fish from your tank.
However, it is not just dead fish that you will need to remove from your tank. Fish that are obviously sick must be immediately quarantined, which you can do by putting them into a fishbowl so that they do not spread their disease to the other fish in the tank. You can understand if fish are sick by looking at their movement in the water. If the fish are sluggish in the way they move (you must compare with how they move normally), or if they are spending a lot of time behind the rocks or plants in the aquarium, or simply lying lethargically on the aquarium bed, then something is wrong with them. The eyes of the fish could also be indicators of disease. If there is anything different with the eye, first remove the fish from the aquarium, and then get it checked by a qualified person.
But the most difficult thing is to remove a live and healthy fish from the tank. There are many reasons why you would want to remove a live fish. The fish might have outgrown the capacity of the tank, or the tank might be getting crowded, or simply the fish might be a danger to other fish due to its violent nature. Betta fish are notorious for attacking other fish in the tanks. Whatever the reason may be, removing live healthy fish from the tank is always a challenge.
There are some obvious problems. Live fish will squirm and wriggle around a lot in protest when you try to remove them. Some fish, like the surgeonfish, will also harm you if you try to touch them. Then there are toxic fish that you have to be worried about. Also, when you try to remove a live fish, there will be a lot of thrashing and flailing about, due to which the entire setup of your aquarium tank could be disturbed.
Your best bet to take out a live fish from your tank would be to use a line, hook and bait, just like you do when you go fishing. But you will have to use a blunt hook so as not to harm the fish. Tie up a morsel of the fish’s favorite food on the hook and dangle it in the tank keeping the line tight. The fish will take the bait, and then you can transfer it to another tank.
Another way to do this effectively is to confuse the fish. Most fish are startled when there are sudden changes in light, because deep under the water in their natural habitat, there are never any quick light changes. Anyways, you can keep your tank in darkness for several hours and then suddenly put all the lights on in the room. Taking advantage of the confusion of the fish, you can manually take them up, using protective gloves. An alternative to this is to come up to the tank in the middle of the night and then to shine a torch suddenly at them.
Putting fish into a tank is many times easier than removing them, especially if you want to retain fish that are still alive. You will need to be patient and careful so that you accomplish the task without harming the fish in question and the other inhabitants of the tank.