Mh is just a term used to describe a bulb / tube that generates wavelengths of light.
(check this thread about wavelength and kelvin:
https://forums.saltwaterfish.com/t/204927/lighting )
You can use a 8000k light and then get either a 10000k or 18000k(better known as the 50/50) and run that at the same time. Corrals and anomones require wavelengths for photosynthisis. Some people blast their critters with really bright light, others will run a lamp that puts out a massive amount of 'blue' light.
Myself, I run a 'daylight' lamp and my 50/50. Technicaly, the 50/50 puts out more light than the daylight lamp. But the visible light we see makes the 50/50 look slightly dimmer.
Go to a web site that manufacturers lights for us fishy people and look at the sepcifications for the different lights. They all have different peaks and vallies in the wavelength output in their spectrum.