1

Works great. I would rather not use it because is is colorful enough even without UV that I think of it as messy, and drain and flush after finding and fixing leaks, but maybe I add too much, or maybe I should just not worry about that and rinse everything when done. It is quite water soluble and rinses clean off. My son calls it "predator blood", looks the same. Definitely helps finding obscure leaks on messy engines. Be sure to put it in the radiator. If put into an overflow tank, especially a non pressurized type, it may require a few heat cycles to transfer enough to where it matters to be useful. Obviously, won't help with a head gasket leak to the combustion chamber, unless you look with a borescope, maybe after letting it sit pressurized a while. Head gasket leak to crankcase (oil contamination), you shouldn't need this stuff for. The milkshake is perfectly fine for that.

Works great

Was skeptical at first but used it and it makes it so much easier to find a leak and most of the time you dont even need the flashlight to spot it. Color is nice and bright to see definitely worth the money id buy again. Worked great for us even though the radiator is shot.

According to the advertisement, you only need 1 ounce per cooling system. The actual bottle I received stated 1 ounce per gallon, which was also confirmed Supercool's website. Glad I bought the 8 ounce bottle. Instead of using 3.2 ounces for my application though, I went in the middle with 2 ounces which proved to still be effective.

The dye shows up well under blacklight.