* Distilled water: Distilled water is pure water that has been removed of all dissolved minerals. It is the safest type of water to use for fighter fish, but it can also be expensive.
* Reverse osmosis water: Reverse osmosis water is a type of filtered water that has been removed of all impurities. It is a good alternative to distilled water and is often more affordable.
* Spring water: Spring water is water that comes from a natural spring. It can be a good option for fighter fish, but it is important to note that spring water can contain high levels of minerals that can be harmful to fish. If you are using spring water, it is important to test it to make sure that the mineral levels are safe for fish.