Led Lighting

[jonnyuk]

not sure if this goes in here or the hardware section as my question is really geared towards plant growth

will the below

Marineland Double Bright LED Light - 18 in. to 24 in.
My link

be enough to encourage could growth with plants. i've read contrasting stories, its seems to be a consensus that they are a no no for reef tanks and allot of people think the LEDS just won't cut it for planted tanks. my tank in particular is 16" tall, width about the same as the light strip, 15".

what about for low tech systems though? Another major problem is i can't find it in the uk and allot of online places won't deliver to uk (not directly asked anyone though).

overall seems a good product and cheapish, granted you can't put a timer on the moon leds separately but that's not an issue for me (i have read a good post on how to put a separate power source to the moon led's.

 

[SuperColey1]

It depends if they are high power ones (1W,3W+) or just standard 3mm, 5mm ones.

You have to be careful as some of the 3mm, 5mm ones are advertised as 'ultrabright'. They may be in comparison to other 3mm/5mm ones but that does not mean a lot.

High Power LEDs are a big yes, yes for reef and planted. The only problem being people tend to overestimate what they need because they are used to tube lighting and MH.

3mm/5mm is OK for decorative /effect purposes and not a lot else.

AC

 

[jonnyuk]

this site seems to have abit more info. they are 1w per led from what i can gather.

My link

The smallest will be for aquariums 18" - 24" long and has 6 one watt LEDs outputing 450 lumens.
The middle model is for aquariums 24" - 36" long and has 8 one watt LEDs outputing 600 lumens.
The longest lamp is for aquariums 36" - 48" long and has 16 one watt LEDs outputing 1200 lumens.

most of this type of spec goes over my head to be honest.

 

[SuperColey1]

Firstly Lumens is a pointless measurement for aquariums as the forum states. However the forum then says a PAR or Lux meter would give them some numbers they could use. Par yes, Lux - No. Lux is just as rubbish as Lumens.

As gauge of how pointless Lux is. Take some LEDs and fluoro/MH of the same wattage. the fluoro and MH will have higher Lumens and Lux than the equivalent W LEDs. However the LEDs will far outperform both the fluoro and MH in terms of PAR.

Secondly I'm not sure I would trust a unit that can' get the advert right.

The advert states the units have 6,8 and 16 LEDS whereas the pictures show 9,12 and 24 LEDs!!!

Not so professional so far.

The one thing they do have right (by accident) is that LEDs produce light virtually solely in the usable range where other lighting produces som like ultra-violet outside of the usable range. Where I say 'by accident' I mean that they have accidently shown this info because they are warbling on about spectral colourations which again is somthing we tend to ignore.

How much credibility can my statements have? See below:


Maybe I should have patented the design of my DIY one. See any similarities?

The end of my statement would be this. Even going by the pictures and not their incorrect mathematic advertising their units are not supplying anywhere near enough for plants even based on their sizes and tank size suggestions.

I have 15 x 3W in my unit and that is a 30" They would have me put a 24 x 1W over instead and that would mean overhang and wasted light at the ends. Also you don't kow what they are running these LEDs at. they may be 1W LEDs but will ilkely be underpowered to make them last longer rather than maxed out.

So I would need 2 of their units to match mine and even then it may well not match because of the 3W vs 1W intensity difference and the lost few inches of light at the ends.

So get them for an absolute low light planted tank and you will have the coolest looking low light tank around however for medium to high you're gonna need 2 or 3 units and I doubt many tanks have that much rim available to put the legs on.

AC

 

[jonnyuk]

what you say makes allot of sense, suppose i just caught up in the LED, affordable, looks cool, might do the job.
i want to change my light because it looks crap to be honest and would rather change to LED now, rather pay x amount in a year or so for LED, maybe LED is just to new right now, seems to be the general opinion.

i was following your DIY led setup, very impressive. maybe when i get the bottle i'll give it a try but on a smaller scale.

my tank is low tech in so much that i only have my lights on for 6 hours, no CO2 but i do dose jbl 24 hour ferts daily with a jbl fert substrate. currently have an 18w aquadistri light (two tubes in one ballist so is that called a u tube or something?).
my plants seem to like what i'm doing with good slow growth.

maybe i should stick with what i have and be greatful my tank looks good, as my wife tells me everynight when i say "can i have a 60ltr tank, it would fit just there"

 

[ian]

maybe i should stick with what i have and be greatful my tank looks good, as my wife tells me everynight when i say "can i have a 60ltr tank, it would fit just there"

women...the bain of many a fishkeepers lives.

I like the look of LED's and like you Jonny, i shall one day probably use them. AC's lights are great, even though they are DIY lights, they really look good and professional over his tank.

or we could save up and buy one of those ADA £1000 lights!

 

[jonnyuk]

women...the bain of many a fishkeepers lives.

yes i have learned that one very quickly

those £1000 + led lights are the things that drew me to the marineland stuff, not a truer word said, "you get what you pay for".

if they where sold in the uk i'd probably go for it, if they where pants take it back.

 

[SuperColey1]

would hold off for now. Most of the LED retail units are focusing on the super highlight reef hobby.

This is a problem with most retail luminaires of any lighting type.

One day they'll get it right but of course they will focus on where the most money is.

AC

 

[jonnyuk]

AC, i've been reading through your DIY led setup again and come with something a little different. was thinking of something like this

My link

it will then need this so i can put a normal plug on the end

My link

given its working off 240v, you could stick a standard dimmer unit on it etc.

the problem i can see is its too much wattage and the spread would not be right, for my tank i'd need two of them unless i could rig a good enough reflector.

maybe i'm barking completely up the wrong tree here ??

 

[SuperColey1]

Lol. Nitro7 already gave you the answer for that kind of LED on the thread in hardware

3/5mm LEDs are fine for effect but not for plants or reef.

We need to start to get used to not gauging what looks bright to us as putting out a lot of light.

For example if you look at 1 high power LED you will have a white spot in your eye for hours. that is how bright it is. 1 won't be any good over a tank of more than 2 or 3 litres though.

Similarly if you look at a fluorescent tube you will get the white line in your eye but not for long. However that will be OK for plants.

You see what I am saying. Brightness is both perceptive and deceptive. What can blind you from looking at it may not necessarily be putting out much light at all in comparison to something that doesn't blind you.

Those 3/5mm items may appear to light up a tank well as you have seen however penetration will be an issue. They are using 50-100 to get the light that 1 high power LED will give. Penetration is down to point source lighting.

That is why pushing loads of power through a T5 tube and making it a T5HO suddenly gives more penetration.

You then have to weigh up that the intensity due to this penetration will be huge direct below the tube and less away from the tube.

With high power LEDs we can spread them better. They are not forced to be in a long line or in a panel. they can be spread like grids.

Add to that we can then focus the light differently according to purpose to spread it better. Think of a fluorescent reflector but 200% better and many more options. Also LED will only put light out of the front side therefore nothing lost by restrike or reflector quality etc.

Therefore on a reef LED setup there will be more LEDs, closer together and you then focus the light with a lens that has a narrower beam maybe 8 - 20º. With a planted setup you use half or less LEDs and then focus the light with a lens that has a wider beam. I use 45º.

For either you don't really need to use lenses at all. You get great spread without the lenses. Perfect in fact but that then means you have an open bottom unit (see my first build) and that means glare etc.

The LEDs I use have 'lambertian' dies. that means the little plastic piece over the LED is a hemisphere and therefore the light emits 120º maybe more and pretty equally too. There are different types of die so that you can direct light without lenses differently.

The reason I have the lenses is more aestheitc in that it means the bottom side looks tidy and also it means when I am laid out on my sofa watching the TV I don't have a direct view of 15 LEDs in the corner of my eye. Instead I have a much reduced glare from seeing just the lenses glow from an angle

AC