Gents -

I have a couple of questions regarding lighting. I've been mooching all sorts of great information from you guys lately in my quest to convert my 42G Hex saltwater fish tank into a reef tank. My past questions have been regarding filters and live rock, and I believe I have those issues under control. I have purchased a CPR Bak-Pak 2R and have plans to meet with Rat Boy on Sunday to buy some of his base rock and eventually purchase some live rock from Tim once I get the base rock and protein skimmer setup and working well.

My current lighting is a single 250W MH with a 10,000K German bulb. I don't have any of these fancy 'Icecap ballasts', but instead I purchased a normal ballast from one of the lighting stores here in town and keep the ballast in a separate enclosure away from the tank. I also didn't buy one of the expensive reflectors, but instead settled on the metal flashing that is used in roofing. The light seemingly works fine and looks good in the tank, buy will this work okay for the tank when it comes to satisfying corals need for light?

Also, I currently only run the light for 4 hours a day because that's the only time I'm really home and supposedly fish (Purple Tang and Tomato Clown) don't really care about light(Though they seem to be more active when it's on, so I usually keep it on more on the weekends). When I switch to a reef tank, will I need additional lighting above and beyond the 250W MH or can I just reset the timer so that it stays on for 12 hours? I read some posts that I believe mention that some run actinic light for part of the day and then MH the rest. If I need additional lighting, what would you suggest that would fit inside of a hex tank's canopy? I only have about 18" of space... I have yet to learn enough about coral to pick which particular types I want to keep, so I can't really provide any detail in that area to help narrow my question, but I would like to make sure my equipment will provide a good starting ground for future expansion.

Finally, if metal flashing isn't an acceptable reflector, does anyone else have any clever ideas on alternative to spending $40 for a piece of shiny metal, or is there some valuable reason why I should spend the $40 (I built a custom canopy so noone can see my 'cheapness')? Would simply using mirrors work well enough (and presumably better than flashing)?

And REALLY Finally, my MH is about 7-8 inches above my water (is this too close to the water?), and I currently keep the original glass top on the tank. Should I be doing this, or should I just have the light directly above the tank without any sort of protection? Previously I had a puffer fish who spit water whenever he got hungry and I was concerned that he would spit water onto the light and make it explode. The unfortunate part about the glass top is that it gets encrusted with salt and the light doesn't seem to shine through as well. I could also purchase some heat-resistent plastic and create a protective cover over the lights and remove the top if you guys think that would be smarter.

I'd really like to hear your opinions and experiences in this area. I've read a number of articles on this board and learned a bit about lighting, but I'd really like to hear your recommendations for what I should do next in the lighting arena.

Thanks, doug.