10 Smart Ways to Use an Aquarium Catch Cup or Specimen Container

Have you ever seen those clear rectangle boxes hanging on the outside of tanks at your local fish store? The aquarium specimen container, or catch cup, is one of the most useful tools in fish keeping. It is a transparent, small container that can be used to observe fish or hold aquarium supplies. Learn about the top 10 ways we find ourselves using catch cups every day at our retail fish store and personal fish tanks.

1. Observation

It can be hard to really see your fish when they are zooming around an aquarium or darting behind decorations, so to get a closer look, catch a group of them with a fish net and place them in a catch cup full of water. You can inspect the fish for signs of disease, select the best individuals for breeding, and sort out the juveniles. You can also use the flat, clear walls to take photos of your favorite species.

2. Transportation

Aquarium nets may be fine for moving a few fish from one tank to another, but this method can be quite inefficient if you have a large school of fish to transfer. Your specimen container can be used as a temporary storage place until you catch all the fish. Then, move them together. To keep them safe from predators, relocate fry to a grow out tank, bring pond fish indoors during winter, or remove pest snails from a single tank for your pufferfish tank.

3. Selling Fish

Fish bags are required if you plan to sell your fish at an auction, fish shop, or online. Place the fish in the container. Once you have the right number of fish, you can easily pour them from the catch cup directly into the fish bag and then seal them inside with rubber bands. You can use multiple containers. The first container will hold the largest number of unsorted fish while the second one will contain the fish.

4. Acclimation

You may need to gradually acclimate your shrimp or fish to the aquarium water if they are new to it. If the animals are small enough, you can acclimate them in the specimen container.

1. Cut open the fish bag and pour the animals and some of the water from the bag into the catch cup so the fish are completely covered in water. 2. The catch cup should be filled with aquarium water. If the water level gets too high, pour some water out of the container. 3. After 15 minutes, add more aquarium water so the water is doubled again. 4. After 10 minutes, add aquarium water to make the water double again. 5. Set the fish aside in a container and net them.

You can also do drip acclimation using lengths of airline tubing. This is a slower process. If fish are racing around in the catch container, you can help calm them by making the room darker and/or covering it with a towel.

5. Breeding

An air stone, check valve and airline tubing can be added to your DIY breeder box. To keep the specimen container warm, hang it inside the aquarium. Then add the airstone to ensure that the fish have enough oxygen. You can then place a few fish inside the aquarium to increase the likelihood of them mating. This setup is also useful for hatching fish eggs. Finally, you can temporarily raise newborn fry inside a catch cup without worrying that they (or the tiny foods you feed them) will escape. To provide shelter for them, add a clump java moss and other live plants. You should also regularly clean the water from their catch cup with a turkey baster.

6. Isolation

You may have to temporarily seperate one fish from the others in several situations. Female mollies, guppies and other livebearers who are about to give birth might appreciate a calm, peaceful environment for their babies. A “birthing room” can be set up to protect the fry from being eaten by larger fish immediately. Additionally, a clump or plants will help the babies hide from their momma.

You could also isolate fish with unusual symptoms or injuries. If you have a fish that is sick or injured, it’s a good idea to keep them in a container with an air stone. This will allow you to closely monitor their health and treat any problems with medication. Read the entire article for more information about treating fish diseases.

7. Mealtime

Fish food should be varied to ensure that your fish receives a variety in nutrients. However, it can be difficult to manage all the jars and packages. Your catch cup can be used as a food container to transport everything from one tank to the next. To feed frozen foods, you can thaw the cubes inside the container. Then use a turkey baster or pipette to pour the liquid into multiple aquariums. The same technique can also be used with live fish foods like baby brine shrimp, blackworms, daphnia, and infusoria.

8. Water Transfers

The catch cup acts as a mini-boiler, and we use it often to clean out an aquarium’s surface or replace water that has evaporated from a nano tank. If you want to test your water parameters using liquid reagents, scoop up some tank water with the specimen container and then use a pipette to fill the test tubes. Some hobbyists use catch cups to place in their aquariums. They then stick the end or aim their Python hook into their container as they refill the fish tank. The catch cup collects the water from the faucet and gently flows out. This protects your plants and substrate.

9. Equipment Storage

Whenever using fish nets, algae scrubbers, or other tools in the aquarium, a specimen container is the perfect place to put them afterwards so they don’t drip all over the floor. Many people use them as extra storage space by hanging the catch cup on the side of the fish tank to keep their favorite fish food, fertilizers, and other supplies all within easy reach.

10. Planted Tank Maintenance

One of the best uses of specimen containers is in maintaining planted aquariums. They can be used to remove unwanted floating plants like duckweed from your aquarium. While pruning, put your stem plant trimmings in the catch cup, and then replant them in the substrate to propagate them.

Now that you are aware of the importance of having a specimen container, you should get the Aquarium Co-Op Catch Cup. The walls are extremely clear to allow you to see your fish and the plastic is shatter-resistant so it won’t fall if dropped. Plus, the extra-wide handle allows you to hang it on large fish tanks with thick walls.