It is not recommended to wear contact lenses while freediving. The pressure changes that occur when diving deep underwater can cause discomfort and potential damage to the eyes if wearing contact lenses. Additionally, there is a risk of losing the lenses in the water, which can be dangerous for both the wearer and the marine environment. It is best to consult with an eye care professional for advice on the safest options for vision correction while freediving. **

Packing air while freediving can be both dangerous and beneficial, depending on how it is done. When done incorrectly or excessively, packing air can lead to overexpansion of the lungs, which can cause lung barotrauma or arterial gas embolism, both of which are serious and potentially life-threatening conditions. However, when done properly and in moderation, packing air can increase lung volume and improve breath-holding capacity, allowing freedivers to stay underwater for longer periods of time. It is important for freedivers to receive proper training and guidance on how to safely and effectively pack air to minimize the risks associated with this technique. **

A neck weight in freediving or apnea diving typically weighs between 1-3 kilograms (2.2-6.6 pounds). The purpose of the neck weight is to help the diver achieve neutral buoyancy in the water, allowing them to descend and ascend more easily without expending excess energy. The weight is positioned around the neck to help the diver maintain a streamlined body position and reduce the effort required to equalize the ears. The specific weight used can vary depending on the individual diver's body composition and diving conditions. **

The best shrimp aquarium will depend on the specific needs and preferences of the shrimp species you plan to keep. Some popular choices for shrimp aquariums include the Fluval Spec V, the Waterbox Cube, and the ADA Cube Garden. It's important to consider factors such as tank size, water parameters, and the presence of live plants when choosing the right aquarium for your shrimp. Additionally, make sure to provide plenty of hiding places and a suitable substrate for your shrimp to thrive. **

A 20-liter aquarium can make a great shrimp tank, as it provides enough space for a small group of shrimp to thrive. Shrimp are relatively low-maintenance and can be fascinating to watch as they scuttle around the tank. It's important to ensure that the tank is properly cycled and maintained to provide a healthy environment for the shrimp. Additionally, adding live plants and hiding spots can create a more natural and stimulating environment for the shrimp. Overall, a 20-liter aquarium can be a suitable and enjoyable choice for keeping shrimp. **

Planarians are flatworms that are often found in freshwater environments, including aquariums. They are known to feed on small organisms like shrimp, so it is possible that planarians could be present in your shrimp aquarium. To confirm their presence, you can look for flatworms with a distinct triangular head shape and a smooth, flat body gliding along the surfaces of the aquarium. If you do find planarians in your shrimp tank, it is important to take steps to remove them as they can potentially harm your shrimp population. **

No, live food for the aquarium should not be poured into the tank with smelly water. Smelly water is a sign of poor water quality, which can be harmful to the fish and other organisms in the tank. It is important to maintain clean and healthy water conditions in the aquarium to ensure the well-being of the aquatic life. Live food should be introduced into the tank in a controlled manner to prevent any negative impact on the water quality. **

No, live food for the aquarium should not be poured into the tank with stinky water. Stinky water is a sign of poor water quality, and adding live food to such an environment can harm the fish and other aquatic life in the tank. It is important to address the stinky water issue by conducting water tests, performing water changes, and cleaning the tank before adding any live food. This will help ensure the health and well-being of the aquarium inhabitants. **