Tank Lighting Comparison/Question

[johanasu]

I have two 20 gallon tanks that I am lighting. They are 20G T so 16" high.

My question is: Can light be deceiving? Meaning, if one light appears brighter than the other, can it actually be providing less light? This may seem strange but... there it is.

Pictures:

Option 1

Option 2

Sorry about the glare, but which do you think is brighter/better?

 

[BobthePhotoGuy]

It could be old/different bulbs.

Also I hope you aren't using the images as a comparison unless you have the camera locked to the exact same settings for both images.

 

[johanasu]

They are two different light fixtures on the same tank. One is 27w and the other is 48w. The pictures are just for the sake of discussion here. I can observe them personally right now

Just looking to see if light is light, meaning the brighter one is brighter even if it is lower wattage (due to different technology).

 

[lockekeyy]

Light is always deceiving. Short answer is yes. In your scenario, if there are particulates in the water, they can reflect that light and make the tank look brighte or dimmer depending on the particulate. Similar is the concept with black sand and white sand tanks. If you light them the same, the white sand tank will show "more" light. Also, the glass might have biofilm which will affect your perception.

 

[lockekeyy]

Bob is also right... As the bulbs age, intensity and wavelength will change.

 

[johanasu]

Yeah that makes sense considering tanks at different times with different setups.

In this particular situation I took the two pictures of the SAME tank with the SAME setup except one with T5HO and one with LED. I wanted to get people's opinions on which looked better and which would be better for mixed corals. I apologize for not being specific or being very clear.

 

[BobthePhotoGuy]

If you are comparing T5 to LED, the wattage "rating" can be very misleading. Actual wattage used is lower with LED's so 10watt LED's will be brighter then 10watt T5's. The wattage ratings are usually based on actual wattage used and LED's are more efficient.

Some manufacturers list an "equivalent" wattage rating to give you an idea of what the output of the LED's for comparison (and marketing) are. The issue is you don't always know what they are comparing to (T5's, T8's and MH also have different outputs for the same wattage use).

 

[johanasu]

That makes a lot of sense Bob, that is basicaly what I was observing but unsure of. I always see LEDs advertised as equivalent to XXXw MH etc. Never sure how accurate those comparisons are.

For these two twenty gallon tanks I can either use our http://www.amazon.com/Marineland-Capable-Aquarium-Lighting-System/dp/B00494JTFU
(24-36" version)
or
http://www.amazon.com/Coralife-Aqualight-Output-Fixture-24-Inch/dp/B002P9MFW0
(24" Two bulb T5HO version)

I switched from the T5HO to the LEDs today and the tanks look great, if a bit white for my personal taste. Perhaps I'll stick with the LEDs and supplement with an actinic stunner. They are in my classroom so money is tight though.

 

[ska d]

Without reading everyone's posts, at first glance option 2 looks better, but that could be the glare in the first one that is throwing me off. Option 2 just looks crisper and clearer. Without judging anything else (spectrum etc..)

 

[Stolireef]

I'd suggest that trying to 'eyeball' intensity is nearly impossible. For example, you can't see ultraviolet or infrared wavelengths. I've personally seen corals burned under LED's where the intensity doesn't 'look' as strong as under a MH/T5 setup.

From an aesthetic perspective, I prefer MH/T5 combo but that's a purely personal opinion. I've seen gorgeous tanks lit with T5's and LEDs.