WaterKeeper, you scrambled my brains with your lighting thread

[Ralistin]

Geee, I hope I can ask this question right now after reading near all of your lighting thread. I think my eyes are going too.

I just wanted to know if you see any flaw in my logic.

I have had my tank for three years. Corals grow well. Polyp extension is decent. Coloration is ok. I have:

75 gallon tank, 4' long about 20" tall.
2 x 250w 6500k Iwasaki MH bulbs mounted 13 inches above water level with reflectors
4 x 110w VHO super actinic mounted 5-7 inches above the water

I believe that I get slightly too much light at 12.5w per gallon. I have decided to go with two Ushio 10k bulbs. I figure with the greater k and less par that not only will I get a bit of better coloration but more polyp extension as well. I might even remove two VHO bulbs to reduce the watts per gallon. Your thoughts?

 

[WaterKeeper]

Hi Relistin,

The proof is in the pudding--is there ever too much light? IMO, not really. A tank like yours, that is doing well, proves that point somewhat. Moving up in color temp is not always conducive to an established tank. Over the years the symbiotic algae have expected a certain spectrum and thrive on it. Changing that could do more harm that good.

The 6500 K that you currently use, supplemented by the actinic, apparently have done well. You can up the blue value of those lights by using a higher K but I'm not so sure you will see that much improvement.

The first thing to note is that the bluer light will change the overall look of your tank. This often leads to claims that, "Since I changed my lights everything looks better". In fact all that happens is a change in visual perception and often change produces enhanced esthetic feelings.

Anyway, the change will not harm anything so feel free to try it. It will also possibly allow you to save a few bucks in energy cost by eliminating the supplemental light.

It will not, however, improve your failing eye sight.