no!
Yes, they can.
snails mostly live on vegetables like lettuce.
There are many chemicals that will kill freshwater snails but they will also kill fish and some will kill plants too. The best way I have found to remove snails is to have a few Clown loaches (Botia macracantha) or a couple of freshwater Puffer fish to kill and eat them.
no. they live in mud.
Yes snails can live in a fish tank, and they can breed.
The same as in the ocean
you can put in sea snails and more brightly fish that you cant get with a heater in your tank
Freshwater snails will certainly eat dead fish, as will a variety of marine snails. There are predatory snails called cone snails that live in the pacific that hunt, kill and eat fish like any other type of predator. They have a type of venemous harpoon that they are able to launch into fish. This paralyses the fish instantly and then the snail eats it.
I recommend anything with water and space for the snails to eat. Basically any freshwater fish tank with be okay for the snails. I must tell you though, never to put snails in with beta fish because sometimes the beta fish will try to eat the snail so i recommend putting them in with goldfish or some other freshwater fish. I have a 10 gallon freshwater tank with a common goldfish and a golden inca snail and they live happily together. I hope this helps!
No, snails and betta fish should not be kept together in the same tank as betta fish are known to be aggressive and may harm or even kill the snails. It is best to keep them in separate tanks to ensure their well-being.
Differnt types of fish tanks will need different levels on nitrate. However, most fish tanks benefit from as little nitrate as possible. Saltwater tanks should have almost no nitrates. Freshwater planted tanks conversely, should have about 10-20 ppm nitrate. For most normal, tropical freshwater aquariums, keeping nitrates below 20ppm is acceptable.
You don't have to, but a small amount of salt for freshwater tanks acts as a soothing 'tonic' for freshwater fish. Follow instructions on the package.