# Led lightning for deep freshwater aquarium?



## ch.campos

Dear all,

I am very confused about the led lightning information on the internet and would like a help from you. I have a 24” deep freshwater aquarium and would like to add a led system for medium or high lighting plants. I have discus fishes and low lighting plants working fine.

To my knowledge I have two commercial affordable options:
1) Marineland Double Bright 36” – that seems to not have enough PAR for medium light plants in such deep aquarium (36 – 48” - (16) 1W 6000K White & (8) .06W Blue LEDs 1200 Lumens) (http://www.marineland.com/sites/Marineland/products/productdetail.aspx?id=2054&cid=5457&mid=5528)

2) Marineland Reef capable 36” - that seems to have enough PAR readings for this deep, but 10.000 k white leds (36 – 48” - (36) 10,000K White & (6) 460 nm Blue 1W LEDs - 2610 Lumens) (http://www.marineland.com/sites/Marineland/products/productdetail.aspx?id=2054&cid=5512&mid=5528)


a) Can I use the Reef capable for freshwater? Or am I wasting too much kelvins for freshwater plants?
b) Adding two Marineland Double Bright could I solve the problem of low PAR? http://www.marineland.com/uploadedFiles/Marineland/11078iMLLEDCharts.pdf
c) Actually how much PAR should I have at the bottom for medium/high lighting plants?
d) DIY system could save more than 50% or solve problems that these commercial options can’t solve?
e) Do you have any other recommendations or right questions?

Thanks very much,
Chris

Aquarium specification:
boyu lh 1000 
40*20*24" lxwxh
83 gal
50W T8
substrate: fondo vivo + fluorite
freshwater
low lighting plants
CO2 system
discus fishes


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## Hoppy

If you have reasonable mechanical skills and some knowledge about electricity and simple electric circuits, you can easily make a DIY LED light that will give you what ever light intensity you want for a 24 inch high tank. For medium to high light you would probably want about 70-80 mms of PAR at the substrate. You will probably want to use Cree XP-G LEDs with optics to narrow the beams for higher intensity at that distance. At most you would need two rows of LEDs spaced around 4 inches apart, or about 20 or fewer LEDs. One row of 10 LEDs would very likely give you that much PAR.

I doubt that you would be satisfied with the Marineland LED lights you mentioned.


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## vai1296

Don't get the Marineland LED lights, i have it for my 10 gallon and it simply does not do a good job of light distribution. The lighting looks cool but is not worth the money and does not really serve our main purpose for a planted tank. I have had this for a little over 2 weeks and don't get me wrong, i do see some growth in my plants (with CO2) but this growth is limited to whereever the led light is pointed. the 6 parts of the tank where the leds are directed is where i see the growth. It is so crazy that i have 4 stems of rotala magenta still tied together and 3 of them and leaning in the light part and one of them not so much. The 3 grew about .5" in about 2 weeks and the other does not look good at all. This is consistent with all the plants i have in the tank. I can only advise you to not spend your money and time on this system. There are soo many t5ho systems you can get which are under $80 dollars just google t5ho and you will find many. If you need help to locate some, please let me know and i will help you search


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## Miira

I have the Marineland reef capable lights over an 18" tall tank and the plants are thriving to the point of needing constantly trimmed. I was starting to get an algae problem until my CO2 setup arrived.


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## IWANNAGOFAST

Check these out if you want an easy set up without having to DIY your own
http://illuminarium-inc.com/content/trident-series

I know they're meant for reefs but they will be debuting their freshwater system this weekend at our club meet. I've seen them in person, very very nice, built in heatsinks too.


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## vai1296

Do you have it just placed on top of your tank or is it hanging? I do not get enough light coverage in my 10 gallon...maybe it is working better for you because of the distance from the led to the bottom of the tank. Since it starts out narrow and the light funnel gets bigger as you go further you might get more coverage this way. So for in my experience the 9" distance from light to substrate isn't a long enough distance for the light to evenly get distributed. Raising it just makes it very dim.


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## Rainer

IWANNAGOFAST said:


> Check these out if you want an easy set up without having to DIY your own
> http://illuminarium-inc.com/content/trident-series


Too bad it's not available in 30". I would love to have a medium-high LED fixture with good light spread and a lunar option.

There doesn't seem to be one on the market yet.


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## IWANNAGOFAST

Rainer said:


> Too bad it's not available in 30". I would love to have a medium-high LED fixture with good light spread and a lunar option.
> 
> There doesn't seem to be one on the market yet.



The freshwater one isn't out yet so it's not on their website, but it'll be shown this sunday. I'll take pics and par measurements and suggest this to them.


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## Rainer

Is it different from the 10k-12k all white option on the web page?


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## IWANNAGOFAST

I hope so! haha I'm not sure, haven't seen it in person, I've only seen the reef version.

I do know though, that it is water resistant, so if you drop it into your tank it'll be ok. Don't use it under water but haha it'll be fine with water splashes too.


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## chiefroastbeef

IWANNAGOFAST said:


> The freshwater one isn't out yet so it's not on their website, but it'll be shown this sunday. I'll take pics and par measurements and suggest this to them.



Those lights look great, I'll keep an eye out for the freshwater version.

Are LED wattage the same as Fluorescent wattage? If have a 17gallon tank, must I get a 30W LED light if I want around 2wpg? Thanks!


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## Hoppy

chiefroastbeef said:


> Those lights look great, I'll keep an eye out for the freshwater version.
> 
> Are LED wattage the same as Fluorescent wattage? If have a 17gallon tank, must I get a 30W LED light if I want around 2wpg? Thanks!


Watts per gallon is of no concern when you start talking about any light other than T12. Light is more complicated than that. The best way to judge light is to use a PAR meter. Otherwise you can use the charts in the stickies, but those are still no substitute for using a PAR meter.


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## Miira

vai1296 said:


> Do you have it just placed on top of your tank or is it hanging? I do not get enough light coverage in my 10 gallon...maybe it is working better for you because of the distance from the led to the bottom of the tank. Since it starts out narrow and the light funnel gets bigger as you go further you might get more coverage this way. So for in my experience the 9" distance from light to substrate isn't a long enough distance for the light to evenly get distributed. Raising it just makes it very dim.


 It's directly on top of the the tank. Maybe your plants are pickier than mine. You may also have a different light, Marineland has 3 different LEDs: normal, double-bright, and reef. I have the reef.


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## ch.campos

Hi hoppy,
Thanks for the answer, I have these mechanical skills...
Leds of how many watts? Cree XP-G or XP-E? And lens?
Do you have an idea of how much would it cost?

Thanks, 
Chris



Hoppy said:


> If you have reasonable mechanical skills and some knowledge about electricity and simple electric circuits, you can easily make a DIY LED light that will give you what ever light intensity you want for a 24 inch high tank. For medium to high light you would probably want about 70-80 mms of PAR at the substrate. You will probably want to use Cree XP-G LEDs with optics to narrow the beams for higher intensity at that distance. At most you would need two rows of LEDs spaced around 4 inches apart, or about 20 or fewer LEDs. One row of 10 LEDs would very likely give you that much PAR.
> 
> I doubt that you would be satisfied with the Marineland LED lights you mentioned.


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## Hoppy

You can get enough light for sure using Cree XP-G LEDs. If you suspend the light a foot or so above the top of the tank, you have to use optics. Which one depends on the front to back width of the tank. You would want the light to spread enough to cover that whole footprint, but not so much that you waste much of the light outside of the tank. How many LEDs it takes depends on what current you run them at, what optics you use, if any, and how long the tank is. And, of course, on what PAR you want to achieve.


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## ch.campos

Hi Hoppy,

Thanks for your prompt answer. I want to install the led just on the top, so I don't need lens? See my pictures of the present tank, and the top that I want to install leds. I will take out the T8 lamps.


I am just afraid of overheating... I can run the leds with 1 or 2 watts (the xp-g is 3W...) to produce less heat, but it will have a tradoff in terms of PAR... unfortunately I don't have a PAR meter.... Any suggestion?

Regards,
Chris



Hoppy said:


> You can get enough light for sure using Cree XP-G LEDs. If you suspend the light a foot or so above the top of the tank, you have to use optics. Which one depends on the front to back width of the tank. You would want the light to spread enough to cover that whole footprint, but not so much that you waste much of the light outside of the tank. How many LEDs it takes depends on what current you run them at, what optics you use, if any, and how long the tank is. And, of course, on what PAR you want to achieve.


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## Hoppy

The way I was able to calculate how much PAR I could get from an array of LEDs was to first measure the PAR vs distance from the LED and vs radial distance out from the center under the LED, for one LED. Then I could calculate how much PAR each of the LEDs contributed to any one spot on the substrate. But, I haven't had a Cree XP-G LED to test. Others have just guessed at how many it would take, then adjusted the LED drive current to get the PAR they wanted. But, without a PAR meter I'm not sure how to do it. It is very hard to judge light intensity just by looking at it.


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## Rainer

IWANNAGOFAST said:


> The freshwater one isn't out yet so it's not on their website, but it'll be shown this sunday. I'll take pics and par measurements and suggest this to them.


Any updates?


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## ch.campos

Hi Rainer, 

I can share my PM with Hoppy: 

If you use just one LED, optics can narrow the beam and would give you more PAR at any distance. But, if you use several LEDs, whose beams overlap, each spot is getting light from more than one LED. If you then use optics, each beam narrows, and you get no overlap. So, in the first case, 2 or 3 LEDs add their beams to get the PAR, and even though the beams are half or a third as strong, their total is what counts. I haven't tested this idea, but with calculations of how much PAR each LED was giving, and how much PAR from adjacent LEDs were added to that, it resulted in that conclusion. I may be wrong, but I don't think so. In fact I suspect an optic reduces the total light somewhat, so you might even get a little more PAR with the overlapping beams.

I hope that isn't confusing. Another way of putting it is that with narrow beams, every spot gets light from one LED. With wide beams, every spot gets light from many LEDs.

Cree XP-G LEDs have a wider beam without optics than the ones I tested, so you might get better results with optics that narrow the beam a little. Light that doesn't make it into the aquarium is just wasted.


Quote:
Originally Posted by ch.campos 
Hi Hoppy,

Thank you again for the answer. You helped a lot. Even months reading the forum I could not conclude a lot of things you mentioned. 

Now I am confident to start my DIY! I have done a small project on autocad inspired on yours from 2009, but I can't attach here.

People in the Brazilian Aquarium Forum almost killed me when I mentioned not using lens... then I ask you:
Why the light intensity should be about the same with or without the optics?
With optics don't you get higher PARs on the bottom? 

Making a small project I would say that for my aquarium 45 degrees lens could employ better the light. What do you think?

Regards, 
Chris


Quote:
Originally Posted by Hoppy 
Quote:
Originally Posted by ch.campos 
Dear Hoppy,

I found a thread you opened in 2009 (Designing and Building a LED Fixture). And like you at that moment, this is an obsession with me! As much I read I understand less. I see a lot of people making the DIY projects for doing, no schematic plans etc. as I would expect. However, I saw that you have done all these plans on the thread above. Based on your experience, could you give me a DIY led lightning specification for my aquarium?

It is a 40*20*24" (lxwxh) (boyu lh 1000). I don’t want to take out the top, I like it closed and prevents from my cat getting into the aquarium…. The lights now are nothing: 2 x 25W (T8) and the leds seems to solve my problem, generating less heating in the enclosed top compared to other lights. Maybe even the leds will overheat there. I live in Rio de Janeiro, temperature average is 68F until 86F.

Based on what I have seeing at the forums, I would start with 4 X 4 Cree leds XP-G, 4” spaced, 80 degre lens and the leds placed on the aluminum top, 4” from the water (or less if I need a heat sink). What do you think?

Thank you,
Chris 

Because your tank is 20 inches from front to back I would use two rows of LEDs across the length of the tank, with the rows about 8 inches apart. I don't have the detailed data from Cree XP-G LEDs that I would need to do a good job designing a light for that tank. You can make it work by designing as best you can for a LED current of 700 mAmps, then, if the light is too dim, you can increase the current to 1000mAmps, or if it is too bright, you can reduce it to 350 mAmps. If you use only 4 LEDs in each row, you may get spotlight effects. If you don't mind the tank looking as if it is lit by spotlights, 4 LEDs in each row should work.

With a small number of LEDs you get the shimmering shadows that some people like. With more LEDs you get a lot less shimmer. So, you need to decide if shimmer is important to you. If it isn't, you could try the LEDs without any optics, so the light from each LED mixes with that from all of the other LEDs. With optics you get more shimmer, but less mixing of the light from all of the LEDs. The light intensity should be about the same with or without the optics, unless you use such narrow beams of light that the tank is very unevenly lit.

Assuming you use 2 rows of 4 LEDs, or 8 total LEDs, you will want to provide a good enough heat sink that you can run the LEDs at over 1000mAmps, if you need to to get enough light. That will require a finned aluminum heat sink, about 10 inches wide and almost 40 inches long, which is expensive.

A Meanwell driver can easily drive 8 LEDs in series, so you would need one that supplies about 28 volts minimum, and 1300 mAmps. You can use a driver that doesn't have dimming capability, if you don't mind removing the cover off of it to adjust the current any time you need to.

Since the heat sink will be in an enclosed light fixture housing, you will need a couple of very small fans to help keep the heat sink cool.

I think that is about the best I can do for designing that light, since I don't have the date needed to do an accurate design. If you have other specific questions I don't mind trying to answer them.


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