Aquarium Lighting Experiment - Metal Halide VS LED

We have two types of light over an 800 gallon aquarium. Left side has metal halide lighting. And right side has LED lighting. We will compare coral growth and color over time. We started by mimicking the LEDs to look like the metal halides using the naked eye. But our end goal is not to light the tank exactly the same throughout this experiment. We will adjust the LED side over time for maximum coral growth to get the most out of the LEDs. Metal halide light requires no adjusting since it is set for maximum coral growth. (We're experts at growing coral under MH.) We will place same species of coral on each side in similar positions.

Aquarium Lighting - Radium Metal Halide VS Radion LED

Metal Halide Lighting - Radium MH - two 400 watt MH plus two 1000 watt MH giving us a total of 2800 watts

LED Lighting - Twelve modules of Ecotech Radion LEDs were mounted using fiberglass unistrut - The reason we chose this light was because it has 5 color channels that are controlled individually. This control allows greater flexibility for manipulating spectrum for this experiment. We want to optimize color and growth of coral.

System Details

Protein Skimmer - Deltec TC3070S

Dosing - Profilux Dosing Unit 4 to automatically dose calcium, alkalinity, and magnesium

Canopy Ventilation - Vornado fans inside canopy pushes in air from outside while an air duct sucks out 80 cubic feet of hot air per minute.

Flow - Three Wave II pumps 1/2 hp model by W. Lim Corp - The return pump will draw 8500 gph from the sump and into the aquarium. Two closed loop pumps will draw 8500 gph each from the aquarium and push the same 8500 gph back into the aquarium through an Oceans Motions Wavemaker that varies flow between 2 of 4 return jets at a time.

Live Rock - 1100 lbs of live rock

Sand - Carib Sea Geo Marine Florida Crushed Coral - We went with big heavy sand so it wouldn't get blown around the tank because of the massive water flow in the tank.

Custom Sump - Pics coming soon

UV - 200 SL Aqua UV

Aquarium Chiller - JBJ 1.5 HP Commercial Series Chiller

Overflow - Three built-in overflow boxes with a total of four 2 inch drains

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2.2.2012 - Coral Close-ups - Slideshow

Coral names below correspond with letters in the picture. Coral names in red exist on both the MH and LED sides and will be used for comparison later.

A – Elegance

B – Setosa

C – Acropora Caroliniana

D – Red Planet

E – Violet Phoenix

F – Blue Staghorn

G  – Rainbow Delight 

H – Vivid Echino

I – Green Polyped Leather

J – Icicle Tort and Tricolor Prostrata

K – Jedi Mind Trick Montipora

L – Chalice

M – Tricolor Acro

N – Oregon Mummy Eye Echino

O – Purple Slimer Acro

P – Bali Green Slimer 

Q – Magnificant Sea Anemone

R – Gold Torch

S – Rose Anemone

T – Montipora Undata

U – Strawberry Shortcake

V - Intergalactic Acropora

1.27.2012 - PAR Readings (click to enlarge)

-Read more about why LED PAR numbers have a large margin of error: Email from Apogee Instuments

-Wattage on each side - 2800 MH (two 400 watt MH + two 1000 watt MH) VS 1680 LED (12 modules at 140 watts each)

-Par meter is pointing on top of coral that the number in the picture is sitting on. See next post for coral names.

-Tank dimensions: 168" long by 36" wide by 30" tall. The viewing window in the picture is 25" due to the canopy

-Some light must pass through acrylic top bracing which covers parts of the tank.

-LED settings were chosen based on making the LED side look as close to the MH side as possible using the naked eye.

-Also, we chose to hang light 15" above water instead of the recommended 10" by Ecotech. We went back and forth on this but we needed the 15" of accessibility to properly get inside and maintain the aquarium. So far, this is working well and coral on both sides of the tank are encrusting.

-Conclusion: Since we do not have an instrument to accurately measure PAR for LEDs, the numbers included for the LED side are "very loose guides." The actual numbers may be 20% higher. Going forward, we'll use our naked eyes and photos to describe and compare color and growth of coral.

1.24.2012 - Radion LED Settings

Screen Capture from Radion LED Software - Lights go on at 9:30 am, ramp up their intensity until 10:30 am, then stay constant until 6:30 pm when they begin to dim down. At 8 pm, they shut off completely. We do not run a night cycle.

This shows the color channel and intensity settings. It's about as close as you can get to an Ushio 20k MH bulb without an ultraviolet channel.

1.2.2012 - Heteractis Magnifica Anemone Under LEDs (just for fun - click on pic to enlarge)

12.2.2011 - Panoramic View (click on pic to enlarge)

Below is what the 800 gallon aquarium looked like on December 2, 2011. Imagine a line thru the center and that will divide the MH (left) and LED (right) sides. The LEDs mimic the light and shimmer of MH very well and it has been hard for some viewers in person to even tell the difference. We will be adding many coral frags to this system over time and tracking color and growth.

Below is what the same tank looked like under all metal halides in 2009. Most of these pieces grew from small coral frags. (click on pic to enlarge)