UV light flow rate

#1
Hi,
I got the AQUA UV 80 Watts 2 inch UV Sterilizer and want to use it in my 550 gallons marine fish tank, not sure what flow rate is the best.

Don't want to kill the good bacteria only controll green water.

some one told me to use the 30,000 mw/cm2 dose, but for that dose the manufacturer chart says will need 3,678gph!! to much flow!, also he recommend me to turn off one light and will need only 1,500-1,600gph flow rate but in that case will only flow 3 times tank capacity per hour.

So, what UV dose do you recommend? 30,000 mw/cm2?
45,000 mw/cm2, 60,000 mw/cm2? and how many times tank capacity per hour will be best?

Thanks!