Lighting wattage

[Petunia]

How do you determine how many watts you should have?

For example: a 30 gallon tank and T5 lighting.
What's the difference if PC, MH, or VHO lighting would be used?

I'm totally new about this and am not really understanding it all. I've been trying to read about it on the net and just keep confusing myself even more.

Is there a site that anyone has found that I can read up on this?

[Geoff]

the biggest difference between the lighting choices boils down to whether or not you need a point source light or diffused light source. Mh's are a point source. all of the light comes from a very small area. this has a much greater penetrating power than a diffused source. this is why MH's are recommended on tanks deeper than 30". a flourescent just can not penetrate the SW to that depth and produce enough energy for photosynthesis in a lot of the corals we like to keep.

if your tank is shallow than a diffused light source can work just fine, it comes down to how much you pay for electricity. MH's are very efficient at producing light. this is why they are so popular.

the drawbacks for MH's are the heat they produce and the initial cost.

G~

[hng]

I'm setting up a 30 gal tank as well and I went with VHO since it was relatively shallow (16 inches tall) and I already had an ice cap ballast.

HG

[Krux]

Most of the selection as geoff hinted towards is going to depend on what you want to keep in the tank. if you are going to keep lower light corals then a flourecent technology would work perfect. if you want to keep things that require a lot of light, then smaller halides may be a good option. you are going to get more light for your energy dollar spent on halides, and in wisconsin the summers shouldn't be too harsh, but there isn't a need to spend that much money if you really want to keep things like leather corals, ricordea, mushrooms, and zoanthids.

[Loverotties]

It depends on what type of Corals you want to keep.