lighting question

[StirCrazy]

Originally Posted by reeferaddict

Uhm... I'm not so sure about this... I have always understood that actinics provide the spectral range that zooxanthellae require for photosynthesis... I could be wrong... but everything I have read points to this.

A 10000K MH contains more of that wavelenght than VHO actinics could ever provide. there for use your MH for lighting requirments for the corals and then ballance the color with actinic VHO's or what ever.

to show what I am meening a VHO URI super actinic puts out about 80 to 100 units of PAR at 12", a 175 watt ushio 10000K MH puts out about 180 units of PAR and my SA 10000K bulbs on a HQI ballast are pushing about 800 units. the biggest problem with using VHO Actinics comes in the form of penatration, the drop off through water is much higher than MH lighting. for example my URI's only have about 25 units at the bottom of my tank (so 1/4 in twice the distance) where my MH are still over 450 on the bottom.

Steve