Sunshine vs. Electric Lights

Adam

Pretty coral are growing in MarksReef Coral Farm. To see the proof, come visit in the evening when the electric lights are the only illumination.

I'll try to grow lots of coral so everyone can have it look pretty in their tanks. 

Aloha  

Here is what I have learned/done so far to try and compensate for those perceived issues:

There is actually more than enough sunlight at this latitude. I visited coral greenhouses at similar latitude, near Detroit MI and Akron, OH in September 2013 (see the pics and my observations here:Underground Coral Greenhouse ). I discovered they cover their entire greenhouses with shade cloth.  Seems kinda silly doesn't it? Build a greenhouse and then cover it with shade cloth because there is too much sun.  I believe these people, like me, had good intentions but they learned as they went along. They also spend a lot of money on summer cooling and winter heating. This is what has spurred my interest in an underground greenhouse with less glazing, limited to south facing and some east facing polycarbonate glazing.

When I returned home I found that during my absence, the sun had descended low enough to begin shining directly on the coral. I had left the blinds drawn up all the way to the top. I lost almost all the coral to fatal sunburn. This was only one of the many mishaps I endured from May - Dec. 2013. I estimate I lost about $5000 worth of coral and it wasn't until just this summer that coral growth finally took off.

What did I do? I learned to keep the window blinds down from September to May. The blinds are adjusted weekly to keep 1/2" slits of sunshine reaching the coral. The slits of sunshine move as the sun crosses the sky. I have not tested it but I'm sure the PAR in these shallow tanks is indeed sufficient, even more than sufficient in the slits of direct sunshine. I'd be happy if someone came over to verify my assumption with their PAR meter. 

Growth is wonderful. I'm seeing what I would estimate is 25% faster growth than the same coral under typical reef aquarium artificial illumination only. Many of you have seen, or at least heard, that coral grows faster under 10,000 K MH lights. Well, I believe it grows even faster in the sun.

What about color? Colors are actually quite good, sometimes even getting better than when the coral arrived from another tank. For the most part, fluorescent lights (t-5 and PC) are running as supplemental illumination from around 4-9pm. The tanks that are not directly in front of the window get 14 hours/day of HO or NO fluorescent illumination. 

In summary, my observations are: 

In fact I've been wondering about doing some sort of cooperative thing where I would take your overgrowth in trade for other coral now or future. Might be a while before the farm gets to the size where it can handle much of that. The system has finally reached a maturity level where stuff is growing so fast it's already getting overcrowded. I'm thinking of having a Coral-Give-Away.

Aloha,  

MarksReef Coral Farm