Hydra 26 intensity on a shallow 21g frag tank.

[Dextereef]

Hello Reefers from frigid Ohio! I have setup a deep blue 21g shallow frag tank. Ive got a hydra 26 overtop of it and it is currently at 15% intensity on all channels. The light is 12" off the water and the water is 12" deep from surface to the bare bottom. I have two tiers of frag racks to accomodate different light tolerances. I know that if I slowly, I mean sloooowly, increase the intensity that I will find the sweet spot but I wanted to check and see if anyone else has one of these lights over a shallow frag and what their experience has been....how high off the water you have them?, what intensity did you start at?, where did you finish at?, are tiered racks just dumb in this shallow of a tank?, can I go quicker on the ramp up (I know the corals will tell me, just looking for commentary) than 2 weeks at a time?

My only experience has been with tanks over 24 inches deep so I am a newbie to the shallow game. Any input is appreciated and for pete's sake stay warm!!! We're headed 10 below the mercury tonight!

Here are some pictograms for everyones eyeballs....

 

[Dextereef]

Bump

 

[Dextereef]

nobody using these on a shallow frag?

 

[Dextereef]

cricket chirp....cricket chirp...out:

 

[mic209]

I run a hydra26 over my 18" cube. I run the blues and violets at 100%, whites at 65%, UV 40%, green 85% and red 40% I do a simple 2 hour ramp up and 2 hour ramp down. I have the light around 11" above my tank, and at my peak settings I get between 150-180par on the sand bed. My highest rock is about 6-7" below the surface and it gets around 350 par. Right below the surface of the water, dead center under the light I get around 550 par. In my opinion these lights are safe to run at higher percentages compared to other LED fixtures.. I would actually have my whites up closer to 75-90%, but I don't like the look with it that high.