I've often been waiting for someone to ask this question and I'm actually surprised no one ever has. where do i start.
A Fazer is basically a fog machine. Fog machines need to heat up for 15 minutes this incorporates a heating element that create your fog/haze effect.
We don't actually call this machine a hazer. however many other manufacturers consider them Hazer because they provide a continuous amount of Fog/haze without the big blast of smoke.
So these are considered heater based hazer that utilize water based fog fluid.
You can buy heavy fluids which have a long hang time or quick disapating fluids that don't last long and disipate much faster.
These fluids are in the fog machine catagory.
Then you arrive at your compressor based haze machines.. these machines don't require heat up time, simply power up and instant haze.. these are also true hazers. and with true hazers an oil or mineral based fluid will provide better reflective particles and less smoke, allowing your lights to look really good but not get all that smoke.
The drawback to these is they usually have a compressor sound to it like a generator and the oil residue leaves a thick film of oil on everything when used in an install over a period of time.
Very dificult to clean.
So the solution to that is to use a water based haze fluid for your compressor hazer. the problem hear is that a water based fluid never looks as good as an oil based fluid and many people expect the same results.. fact is oil based fluid looks better.
So to answer Serra's question... Water base haze fluid looks very weak on the HZ300.. it will haze and a customer of mine resently told me they use water based haze fluid on the HZ300, however i've seen it not work so good. you need an HZ400 or better for the water based haze fluid to work better.
To answer Ricks question a Fazer is half the price of an HZ400.
For the club your in you need to stay with a water based formula and the FAZER (X-310II) kicks butt in that enviornment.
X-310II Fazer offers blue indicator LED's on the fluid tank specifically designed for dark enviornments so that when those LEDs turn on that means you need to add more fluid.
Running foggers without fluid is what causes them to malfunction so this feature will allow your machines to last a long time.
Have fun