K-1 is the type of kerosene you should purchase. K-1 is the best kerosene that you can purchase. It is so clear that it looks like tap water. It is actually a form of distilled gasoline. In other words, it has been purified very well.
Use Pure Fuel
Pure fuel is very important because it keeps the stove or heater running well, the wick clean, and the safety improved. Many problems occur from poor choice of kerosene. Many people do not realize that saving a few dollars is actually very expensive and time consuming, in the long run. The extra effort to get good fuel is totally worth it.
Only Use K-1
Some people try and use K-2 kerosene. This fuel is lower grade and should not be used. Some enthusiasts say to go K-1 or don't use kerosene at all. This may seem strict, but it shows the importance of using the proper fuel.
How to Spot Bad Kerosene
One way to know, if the kerosene is bad, is that it will have a yellow tint to it. You may also see particulates floating around. If you have doubts, don't use the fuel. Instead get something clean and clear because it will save you a lot of hassle down the road.
Use a Hydrometer
One way to check kerosene, is to use a hydrometer, to check, for specific gravity. The hydrometer will show kerosene between .79-.81. Each type of fuel has a different weight and that is what the hydrometer checks.