vho or pc

[tonyzick]

I'm now starting a new 75 gallon reef tank.I would like to keep hard corals and some porite corals.which lighting is better 440 watts of vho or 384 watts of power compacts.which ones do you recommend.or should i get 2 175 watt metal halides with 2 65 watt actinic pcs,except im worried about the heat created by these and when i mount these to the canopy do i need a glass to cover them or what do i use.

 

[hondo]

It's really a matter of personal choice between PC or VHO. The new PC 03 actinic bulbs are excellent, a huge improvement over the previous 7100 blue PC bulbs. I would have to agree with Baron on his recomendation of a mix of MH and PC which would allow you to keep any coral or clam you wanted.

 

[tonyzick]

Thanks for your help but what do I use in between the light fixture and the water or do i use nothing at all.

 

[hondo]

don't use anything between the water and the lights. any glass or plex you put in between will filter out some of the light intensity no matter how clear it appears. Also salt will get on it and further reduce your lighting. Most of all though a glass cover will reduce the gas exchange for your water which could be a major problem. If your using VHO or PC just clean the bulbs regularly (when they are off and do it gently). If MH is used you should have 8" or more between the bulb and the water to help with reducing heat problems.

 

[josh]

Hi,
Well Hondo is sorta right, with PC lighting you want them as close to the water as possible. So you are left with either having a piece of glass which does filter out some light, although very nominal, or having salt on the bulbs.. which does in effect the same as the glass does. Either way it won't hurt the tank. As for gas exchange, you don't want the whole tank covered, as long as you have some of the water exposed and a powerhead cutting the surfact you won't have any problems at all. I have had a glass cover over my tank with PC lights for years now with no problems at all. While it may not be the best option, with PC lights it is really the best.
-Josh-

 

[tacks]

I've got VHO with nothing in between the lights and the water and haven't had any problems at all.
As mentioned earlier, it a matter of personal preference. Good Luck and I'm sure you'll be happy with what ever you choose.