DreamChip build

[megadeth72]

arduino based controllers all need P with PWM

 

[acabgd]

Here finally the FTS with the DreamChip. I have bought two DreamChips and plan on adding the second one during next week. All channels on this one are running at 700mA, which equals to around 50% of total power.

 

[rkesling]

Is that the 100w or 50w? Sorry if I missed that in the thread!

Would love to see the spread if it was about 6-8" off of the tank.

 

[acabgd]

This is the 100W version.

 

[dartier]

Here is an example on how the light is equally distributed and shadows are rendered using 2 multichip LED's compared to 32 multi-chip LEDs. Notice how the shadow is much more pronounced with the two chips compared to 32 chips. Also how much more evenly the light is distributed throughout the aquarium with multi led's.

The point I'm trying to make here is not that the multi-chips create a problem so much as the use of many chips gives much more even lighting and less dramatic shadows than fewer chips do.

You can consider this tank in the picture a 120 gallon tank with 16-20 watts multi chips on each side in a grid of 4X4 as opposed to a single 320 watt multi-chip on each side. Then keep in mind that you would get even less shadow effects the more chips your loosing such as a 5 X 5 grid of 25 chips on each side or even a 6 X 6 grid of 36 chips on each side.

I will agree that the multi-chip with 4 or 5 colors in it does eliminate the disco effect which is a real positive. However I would rather see lower wattage multi-chips that would allow the user to use more of them for more even lighting as well less harsh shadows.

When I built my DIY fixtures, I was worried about this exact thing. Someone on the forum had mentioned that more chips of lower wattage was better than a couple of high wattage chips.

For my 120G (60"x18") tank I went with 10 x 10W 16K/RB450-460nm, 10 x 10W TB 460-470 nm, 2 x 20W 420nm, 2 x 20W 430nm, so 280W in total. I mounted them 4" above the water on 10" wide Al plates without lenses and have egg crate diffusers inserted into the rim of the tank.

I am quite pleased with the result and have nice diffused light. So far I have them running at 55% of power ( 154W ) as I have gradually increased them from 40%. I am not sure I will even go too much higher in power.

Dennis

 

[TropTrea]

I think there is a space for the high wattage LED builds but when you get to 34" or shorter tanks then you will up running more of them at a lower wattage go get an even distribution of the light. As per the diagram I posted above I believe spacing the LEDs more than 12" apart starts giving you harsh shadows. The multi chip does fix the disco effect of being able to seperate the individual colors.

The ideal would be able to have the multichips available in different wattages. With the present configeration on a standard 120 gallon tank I would not want to go less than 8 point light sources such as LED's. Looking at roughly 250 watts total lighting on 8 chips that would mean about 32 watts per Chip. If we ran about 10 watt LED's oo each of these channels it would probably close to ideal. Now if you have a taller tank like some that are 36" tall then the 20 watt per channel would even work out fine. But when your talking 8 chips at even 200 watts per chip that is 1,600 watts of LED lighting that would be extremly over kill. While it might only be only 40 watts per color on each multichip that would have unbelievable penetrational ability unless the mutichips loose effeciency over the single chips.

 

[Lassef]

@acabgd: How is it going, have you started the second chip yet?

Sincerely Lasse

 

[acabgd]

@acabgd: How is it going, have you started the second chip yet?

Sincerely Lasse

No, I plan on doing it this upcoming weekend.

I still have not come up with the real solution on how to "enclose" the whole fixture. Right now it's just placed on a wood plank on top of the tank.

I'm looking for some nicer solutions using some acrylic and glass, to create something resemling a commercial light fixture...

However, what I can say even now is that after initial acclimatization, coral response is fantastic. I am taking photos and will try to document growth.

 

[TropTrea]

No, I plan on doing it this upcoming weekend.

I still have not come up with the real solution on how to "enclose" the whole fixture. Right now it's just placed on a wood plank on top of the tank.

I'm looking for some nicer solutions using some acrylic and glass, to create something resemling a commercial light fixture...

However, what I can say even now is that after initial acclimatization, coral response is fantastic. I am taking photos and will try to document growth.

Please Please add the pictures when you get the second light running. I realy want to see the difference the second chip will make on your tank as far as the distribution of light. For me even distributation is an important thing and with the single unit the beaming effect is very evedent.

This is why I'm a strong believer in multi point lifgt sources rather just a few. Unless you have a very tall tank I think lower wattage and more "dream chips" will be the ideal in the long range.

 

[acabgd]

For me even distributation is an important thing and with the single unit the beaming effect is very evedent.

I don't really get it why people are so concerned with the "beaming effect". The biggest one in the nature comes from the Sun. It's a single source of light, the shadows are more than evident, especially when shining from right above like over tropical reefs.

I would say that T5 lighting is much more "unnatural" than a single led. There is no "continuous coverage" in nature.

 

[Lassef]

The beaming effect can be adjusted with the distance between light source and water surface.

Personally I like to have my aquarium in different light regimes - its more of a living machine that way

Personally - I´m going to have 3 of these chip over a 120*65*60 cm aquarium. The middle will probably be a little bit higher than the other two. I´m working with 60 degrees lenses in order to have a high PAR reading already at low effects.

Sincerely Lasse

 

[TropTrea]

If you want to compare it to nature then you need not just the point source of the sun on mind but entire sky. To mimic that effect yu would have one 100 watt LED as the sun plus 10 10 watt LED's around it from basicly all areas. And if you wanted to stimulate a cloudy day you would reduce that centeral 100 watt LED to around 15 Watts.

 

[megadeth72]

no you dont, the sun casts shadows, never been diving/snorkeling?

 

[TropTrea]

no you dont, the sun casts shadows, never been diving/snorkeling?

yes it casts a shawow. however the shadow still has light in it at roughly half of what it is direct sunlight. With a single point light source that ratio is way down to 1/10 if your lucky.

Also unless your in perfectly calm water without a ripple you have beams of light comming from every angle, as the light is refracted from the waves.

 

[megadeth72]

just be aware when you place corals, I cant stand the look of VHO/PC or bock of led lit tanks, it looks fake to me, some led tanks have shimmer, but most just look too evenly lit

 

[acabgd]

yes it casts a shawow. however the shadow still has light in it at roughly half of what it is direct sunlight. With a single point light source that ratio is way down to 1/10 if your lucky.

Also unless your in perfectly calm water without a ripple you have beams of light comming from every angle, as the light is refracted from the waves.

This is exactly what I have from one single led, as I'm using the X-Aqua which creates ripples/waves on the surface.

I still think that comparing Sun to a 100W + 10x10W leds doesn't make any sense. There no "smaller Suns" around our own in the sky, only one sun and the reflection from the atmospehere.

At the worst, it would mean 1 100W led + a long single actinic T5 across the tank.

 

[Lassef]

@ TropTrea

You are right in that you will have some parts in the upper part of the water there it is a risk that you do not have so much of light. For my part it will be maybe three small upside down cones. For me - it does not matter because I´m not going to have any corals there. These chip combined with lenses are so strong that from 10 cm from the surface - you will not with your eyes se any shadowing.

Sincerely Lasse

 

[TropTrea]

This is exactly what I have from one single led, as I'm using the X-Aqua which creates ripples/waves on the surface.

I still think that comparing Sun to a 100W + 10x10W leds doesn't make any sense. There no "smaller Suns" around our own in the sky, only one sun and the reflection from the atmospehere.

At the worst, it would mean 1 100W led + a long single actinic T5 across the tank.

Yes the 1 100WAT LED would duplicate the single SUN however there is aqlso that reflection from the atmosphere. This is what brightens up the shadows instead of them going almost completly black.

Yes the 1 100 Watt LED with a florescent Bulb would be much closer if your looking at combining florescents and LED's But for the sake of staying with all LED's the series of 10 of them at lower wattage would be the closest I can imagine. And with the T-5 bulb I would not use an Atinic but something like an ATI Blue Plus. You are trying to duplicate the blue sky not just the near UV light from the sky.

 

[jsjonesrdh]

acabgd

I did not see any post about it but do you plan on supplementing with any blue? Would you mind pming me on where I could source one of these chips?

 

[Lassef]

These chips have 5 independed channels - 2 Royal Blue, 1 actinic and 2 white.

Sincerely Lasse