Light height?!?

[ReefJunky]

I've been playing with it trying to figure out what is the best height for the light above water on the frag tank and get diff readings from diff corals. It's a 48x24x10 with a 48" WavePoint 4 bulb pushing 2x ATI Blue+, 1x ATI Coral+, and 1x KZ Fiji Purple. I have also added 10 Cree blue LEDs mounted 5 on front of fixture, 5 on rear. Here is an old pic (light height is actually about 6" higher now) and the added LEDs.
[attachment=1]ImageUploadedByTapatalk1356292764.540877.jpg[/attachment]
[attachment=0]ImageUploadedByTapatalk1356292829.061148.jpg[/attachment]

Problem I'm noticing is some zoas are 'pancaked' on the plug where as some are stretching 3/4-1" off the plug. Maybe it's normal as I've read there basically 3 types of palys and one type (super-paly genus I think) does stretch. Just looking for some feedback/experience on how other have lit there shallow tanks. Thanks!

 

[Eckolancer]

I have found with my leds that are about 4" off the water level. My zoas and other corals do well at a depth in water of about 20" so 24" total away from the light. Any closer and they all seem to fry. Further they seem to be ok but some zoas do stretch.


Sent from inside the shark tank!

 

[Guppy Breeder]

Ive noticed the same thing reefjunky some of my zoas are flat some stretch some dont

 

[ReefJunky]

@Burbarry wrote:

My concern is your light is traveling through 20" of water which wouldn't be the same intensity as 20" of air as water washes the light more than air, right?

 

[Eckolancer]

I agree just wanted to give you my prospective of my tank. From what I understand water distorts the light.


Sent from inside the shark tank!

 

[ReefJunky]

Yeah, I def appreciate it! Not home at the moment, but I would guess its roughly 24" above the water. I'll post that when I get home to help.

 

[Eckolancer]

Also my Leds are on a constant power supply right now set to almost max. Im getting ready to redo my power supplies and add a few more colors to it as well. On top of that I bought a VDM for my apex to try and hook the leds to lightning setup, just for weekend rain shows


Sent from inside the shark tank!

 

[ReefJunky]

Yeah, my LEDs are on a constant meanwell driver, WavePoint only has a single switch so I can kill the switch and keep the blue LEDs for eye candy.

 

[melev]

12 - 16" above the water won't hurt anything, and give you space to work. If your corals seem like they lack in some way, lower it 2" and wait a couple of weeks to gauge the results.