Mobile Bay Reef Keepers

I am setting up my 18 gallon nano and am going to run 175 watt MH, do I need supplemental atinic lights to go with it, there won't be much room left under the canopy after I install the 175 MH. If I used 20K do I really need the supplemental? Thanks Dave

I think that depends on how blue you want it. I run 150 HQI 20K and don't supplement with additional actinic because I think it is blue enough and don't want my corals to look "fake".