Darren, I found your lighting set up :)

[Delphinus]

IMO if sunlight causes a nuisance algae bloom in a tank then something in the system is out of balance.

Seriously, the only reason I don't suggest that we all run out and put our tanks in full direct sunlight, is on account that we're more likely to cook our tanks than anything else; if we don't put into place some serious tank cooling.

Some coral prop outfits and wholesalers are in greenhouses where there may be MH lighting but it is supplemental at best. If you're ever in the Detroit area you HAVE to pay Tropicorium a visit. This place is so neat! It's basically a greenhouse the size of a smallish garden center, but instead of plants, it's full of tanks with corals under various stages of captive-prop. When I was there I was soooo tempted to buy some of their mangroves, but I chickened out on account that I don't know if it's legal to carry mangroves across the border (no idea if they're on CITES or not ... wasn't worth the risk of not knowing.)

But I digress a little, whoops, sorry :rolleyes: ... sunlight in and of itself shouldn't cause a bloom. If it does, then something else needs to be looked at. It may, however, risk heating a tank to unacceptable levels, thus it should not be attempted without a well-thought-out plan.

[Achilles]

I agree with Tony to an extent. I believe that sunlight can cause an imbalance in a system simply because suddenly the system is recieving a great deal more energy than it used to. The system needs to adjust to this influx of energy. Just like adding 400 MH's to a tank that previously had NO tubes... for a while new algaes may pop up, but the system will re-equilibrate given enough time.

One last thing of interest I would like to share, for I to hope to one day have natural light as part of my reef display. I saw this type of light duct on one of Bob Villa's Home Again programs a few years back. It used something similar to a flexible dryer duct to bring light down from the roof into hallways and rooms within a house. Sort of a miniature skylight that you could moderately bend and flex into a position you wanted. They were about 4 inches across and looked perfect for the task. I am concerned about what would be lost (Spectrum etc.) from the light however...

Anyway, all these points are IMO.

Cheers!

Jeff O'Neill