What to use for actinic subliments?

[Delphinus]

Yeah, I'm not real certain if VHO is a "necessity." (With that said, I do use VHO myself.) Another factor to keep in mind is that with the electronic ballasts (Icecap, Workhorse), you can overdrive NO lights, so you can get a little more oomph out of the lights but at a lower cost per lamp.

[danny zubot]

Just my 2 cents here.

Although VHO may not be required for actinic lighting it is important to note that lighting below 480 Nm is still absorbed by corals. If you have ever turned on you actinics in the middle of the night you will see corals react to the light.

Low frequency lighting can penitrate to lower depths than higher frequency lighting, and this radiation that is barely visible to the human eye can still have a profound effect on coral growth. IMO VHO actinics are not needed, as NO actinics will reach lower depths with more ease than say a 10k or 50/50 bulb. It would be over kill, kind of like putting 400 watt MH on a 20 gallon nano tank.