is there actually any different between rock salt and aquarium salt?

Answer 1

Rock salt is often far less pure than aquarium salt. Loads of various trace minerals can be left in rock salt. This would be fine if you knew what trace minerals were there, but with no way to know I wouldn't trust it to use in a tank.

If you are talking about salt for a brackish tank, personally I would suggest you use a salt made for marine tanks such as Instant Ocean.

MM

Answer 2

YES. rock salt is only one type of salt. marine salt is a mixture of many many different salts. the doctor wellfish freshwater salt is actually a marine salt, as for other brands i cannot comment.

some commercial forms of rock salt are from evaporating saltwater but alot is mined as well, but i would say theyre either mixed or impossible to know where it originated form. but most "rock salt" sold retail is sodium chloride only.

ps pickling lime is also one salt calcium hydroxide, commenly used as a "buffer" which is dripped into saltwater aquariums to stabilize alkalinity add calcium and keep a high pH and is not a replacement for freshwater or marine salt.

Answer 3

if you are looking for other sources of aquarium salt try kosher salt or canning and pickling salt. they are the same thing.

rock salt is the basic mineral and usualy has other stuff in it.

Answer 4

Rock salt takes longer to dissolve as well. Be careful not to burn the fish with it...