[BigLar]

I need to decide what to supplement 3 400w Iwasaki's with. I have decided on buying the Icecap 660 ballast, but have not decided on what bulbs to use. Should I go with VHO or PC? What would you do?

Also, how many bulbs will I need for a 180gal?

[JG]

I would go with at least 4 VHO actinics

[icemark]

Go with VHO. Replacement bulbs are cheaper, you will need fewer bulbs over that size tank for the same wattage, and IMO VHO bulbs are brighter.

Figuring your tank is 6 feet long, you would need at least four 48" VHO bulbs staggered for 440 watts, or 4 34" PC's for 384 watts of light.

With that 660 Icecap ballast you can always try both, using two 48" VHO and two 34" (96watt) PC's at the same time and decide for yourself.

[golfish]

Even with 4-110 VHO's you might have a hard time making the 3 400 watt Iwasaki's look good. Its a start and you can always add more light with another ballast. Have you thought about using a 20K in the middle of the tank?

[scubadude]

I think golfish has a good idea....use a 20k in the middle then get 2 or more VHO actinics

[BigLar]

What kind of 20k and how many watts? Are you saying that I should replace my middle Iwasaki with a 20k?

[golfish]

Yes, if you have not bought the ballast yet, a 400 watt HQI ballast with a 20K Radium or Oshram (sp?) would be a good choice. The 20K wont work on a MV ballast, it works best on an HQI ballast.