Are they really necessary? I have two PCs and two actinics and was thinking about taking the actinics out and replacing with 10,000k or 20,000k lights and leaving the PCs. How will this impact my corals?
I've been running 2 55watt 10K's and 1 55watt 20K over my 30 gallon tank for the last year and everything is happy as could be. I'd say replace the actinics with 20K's and you won't even notice the difference of not having the acticinics.