Swim bladder
Are the fish you are reffering to from an aquarium, ocean or lake/dam? :). There aer thousands of different species of fish which preffer to swim at different levels in water. To get the average depth would be near impossible.
It's an Air Sac.
Actually, different species of tropical fish require different levels of kH/gH. Some require soft water, and some hard water. So make sure to research the species before you acquire it!
No. the ammonia levels for fish water are different than in turtle water and are meant for larger quantities of moving water. To suit the habitat need of a turtle yo should find the correct turtle treatment.
Yes, there are many diseases that they can get from bad pH levels and bad nitrate conditions. Different types of fish require different types of water conditions. Pond fish. such as kio, if there waters are not kept clean, they could get fish lice.
A water filter helps remove waste and harmful substances from the water in a fish tank, which can improve the overall water quality. This cleaner water allows for better oxygen exchange between the water and the air, ultimately increasing oxygen levels in the fish tank.
Yes, and at various levels, depending on the species in question.
because their body is immune to the coldness, and also there are different temperatures at water levels. In top of the water during winter can be frozen, but underneath that, there is a slight change with temperature in the water.
To test the oxygen levels in your fish tank, you can use a water testing kit specifically designed for aquariums. These kits typically include a test strip or liquid reagent that changes color based on the oxygen levels in the water. Follow the instructions provided with the kit to accurately measure the oxygen levels in your fish tank.
theres a salt water group and a fresh water group of fish
Every fish lives in a different inviroment.If its a tropical fish and the water is to cold it will die.
Different species require different pH levels and other parameters too. As a general rule most fish will survive a pH of around neutral pH7. Fish like Discus that require acid water around pH5.8 will obviously suffer if given water with a pH of 7.8 to live in and Malawi cichlids who like pH8 would do a similar thing if they are given water that would suit a Discus. Different species different pH requirements.