Understanding LED's

[Sea Witch]

I'm having a really hard time understanding how to choose the right LED fixture for an aquarium. I've been following a few of the threads here on the different brands and different bulbs and different fixture configurations but it's all Greek to me. I don't even have a SW aquarium set up yet, but I want to understand the principles. Most of the time I have the impression when looking at the different fixtures that it's like comparing apples to oranges.

So aside from all the bells and whistles, what's the most important in choosing a fixture? Isn't it PAR at different places in the tank when the fixtures are hung at the same level above the water surface? How much coverage do these fixtures have? Is there anywhere on the net where these things are compared between brands?

I'm interested in creating a spreadsheet with this information in an understandable format for practical applications for aquarium owners. For example, for each of the most common tank sizes, here are the possibilities: brand A and B have equivalent par over equivalent coverage area, they include this or that "extras" dimming, controllability or whatever, and here are the prices compared.

So my question is, what should be included in such a spreadsheet so that the average fish person can choose without understanding all the intricacies of lighting theory?
brand of fixture
brand of bulbs
PAR
coverage area
price
extras
what else?

and is there anyone out there who would like to collaborate with me on a spreadsheet that we can make available as a reference for everyone?

Thanks

[monocus]

well i have a vertex illumina , a vertex iluminux,a marineland led(not reef),am bulding a led fixture for my sump,have 9 watt led bulbs(actually my whole house is led of various wattage)and will be building other leds at a later date.i also have a par meter

[lastlight]

Originally Posted by Sea Witch

Most of the time I have the impression when looking at the different fixtures that it's like comparing apples to oranges.

That's because I think you are since the game is changing so fast. Back when I was into building PCs the processor race was like this too (only not even this bad!).

I haven't entirely ruled LEDs out. I'm going to be looking at lighting next year sometime and I hope there's a resource like you're planning as that'd be pretty sweet.

[mike31154]

Ya, I'm still sitting on the fence with LEDs at the moment because I think there's plenty of room for better pricing & as lastlight mentioned, development of brighter, more efficient LEDs is a race that's far from over. Even with what's out there currently, between manufactured fixtures & the DIY crowd, there are so many variables that you are going to find it just as difficult to document what's happening as you are understanding what's going on in the first place. Not everyone runs the same type of marine system, FOWLR, LPS dominant, SPS dominant and on and on, so I'm afraid it really is up to the individual to do the research and decide whether there's a ready made fixture out there to suit their needs or whether a DIY build is a better choice.

The biggest difference I find with LEDs over MH or T5s for example is the fact that you can customize the colour to a much finer degree since many LEDs are required to provide the same spread as the other lighting technologies. Most serious manufacturers of LED fixtures already give you options as to colour combos. Then there is the choice of optics which is also a game changer as far as focusing the light. Dimming is possible with much greater flexibility due to the ability to fade in & out the different colours. Powerful LED lights with Crees that replace normal household bulbs are starting to show up more commonly on lighting department shelves. Building a LED fixture for your system is already as easy as using an array of PAR 38 (parabolic) spotlights with normal household bulb holders. No soldering, just replace the defective spotlight like any common bulb. Pretty sure these are also available in dimmable versions.

... and to throw a curve in here on the LED thread, have you researched Plasma lighting for aquariums? Seems to have been a blip on the radar recently, but a search will likely still yield some strong proponents of that technology.

[lastlight]

I have seen those spotlight units before that have a reg twist-in end. Why am I not seeing people just wire in standard ceiling sockets above a tank with these clustered? Do the spotlights not keep up as far as the latest and brightest?

[mike31154]

If you search PAR38 on RC you'll find plenty of threads with folks using these. They come in 20,000 K versions and of course warmer colours. They're still quite costly for the powerful versions, but comparable to the pricing of most any other Cree version of a bulb or fixture. I think the original versions lacked options like different optics & the colours we need for marine systems. The manufacturers are starting to come around and offer more choices now though, specifically for our needs.

Here's a link of just one example of a thread with these on RC.

http://www.reefcentral.com/forums/sh...746535&page=11

& link to page with bulb.

http://www.nanocustoms.com/product_i...roducts_id=213

Not really sure I'd go for them, since they do use household power, therefore will have the driver circuitry built into the base, same as Compact Fluorescent screw in bulbs. I'm toying with the idea of getting GU or MR base lamps & run them directly off a DC voltage source.

Here's a dimmable version, lower power LEDs, but could be very useful for certain applications.

http://cgi.ebay.com/Dimmable-PAR38-W...74610053210227

Save yourself a lot of hassle soldering & having half a dozen meanwell drivers to plug in somewhere.

[mark]

would be nice if Sanjay added a LEDs over on his lighting guide. See TJSlayer started a bit of a research comparison with LEDs fixtures, here.