# grobeam 600 light spread



## dansmith (10 Jun 2013)

Hello , I am just working out the pro's and con's of different lighting fixtures for my next aquarium, which will be a 110cm x 40cm x 50cm (h) ada stlyle, low light ,high tech. So I was wondering, having seen the ada aquasky leds, if the same effect could be reproduced with a twin grobeam 600 suspended head to tail say 30cm above the water level. I know that these units have a 120 degree spread and a scale drawing shows coverage , even a lot of light spill, but in reality would these cover my 40cm wide aquarium if set exactly in the middle. I am not really concerned with intensity as I feel I may have to run them at a reduced power for my low light needs , but just thinking about the light spread so there will be no dark corners, Except the obvious driftwood/plant shadows. Many thanks.


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## Reuben (10 Jun 2013)

I have two those TMC grobeam 600 suspended with the output intensity lowered about 5 cm above the water surface on my tank.  The spread of light is good and if they were elevated a just a little I think you would be fine.  Might want to put them slightly off centre (toward the front) even, so you get the light, and what makes these lights great -the shadows falling toward the back of the tank more than the front?

Hope that helps


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## Ian Holdich (10 Jun 2013)

I agree with Ruben, having used 2 of these in the past, I wouldn't use then in anything over a 100cm tank.


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## GillesF (11 Jun 2013)

Hi

I have exactly the same problem: I'm setting up a 90cm low light - low CO2 aquarium and I'm interested in using the Grobeam 600. However, I'm not sure whether I should use the single or dual for a low light setup.

Ian, you recommend using 2 for this size then?

Cheers,
Gilles


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## dansmith (11 Jun 2013)

Reuben said:


> I have two those TMC grobeam 600 suspended with the output intensity lowered about 5 cm above the water surface on my tank. The spread of light is good and if they were elevated a just a little I think you would be fine. Might want to put them slightly off centre (toward the front) even, so you get the light, and what makes these lights great -the shadows falling toward the back of the tank more than the front?
> 
> Hope that helps


Do you have any photos ? also, you say the lights are 5cm above the surface with lowered output , could you tell me what percent you have them running at please?
I was hoping to have them raised at least 20cm from surface to allow the bolbitis I have in mind ,to grow in its emersed form. Does this seem feasible?.


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## dansmith (11 Jun 2013)

Ian Holdich said:


> I agree with Ruben, having used 2 of these in the past, I wouldn't use then in anything over a 100cm tank.


 Thanks for reply, So do you think a tank length of 110cm is pushing it as far as two grobeams are concerned? I was just thinking along the lines of some people just using one tube on their low light tanks. I know leds have a different light quality to tubes, but, It is is a tricky one getting a balance with this low light game.


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## GillesF (11 Jun 2013)

Question is: do Reuben & Ian have low light setup like ours or high light?

@ Reuben: how did you lower intensity, are you using a dimmer?


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## Reuben (11 Jun 2013)

Hello



GillesF said:


> Question is: do Reuben & Ian have low light setup like ours or high light? @ Reuben: how did you lower intensity, are you using a dimmer?


Well I think Ian's setup would be classed as high light as he had them running at max output for his photo period (we was actually using the grobeam 500s I think?)  I've been faffing about and getting advice on here looking to make life easier by lowering output -just so I can make sure my Co2 and ferts are sufficient.  Yes, i am using a TMC aquaray controller.  I currently have this set for max out put from the two tubes as 20%.  The controller also allows you to set on off times and has a ramp facility which lets you fade in and out the light.  I have mine set to fade in out over 180 mins.  This is nice as the light in the tank continually changes.



dansmith said:


> could you tell me what percent you have them running at please?


20% max



dansmith said:


> I was hoping to have them raised at least 20cm from surface to allow the bolbitis I have in mind ,to grow in its emersed form. Does this seem feasible?.


Yes that would be no problem and should work well.



GillesF said:


> I have exactly the same problem: I'm setting up a 90cm low light - low CO2 aquarium and I'm interested in using the Grobeam 600. However, I'm not sure whether I should use the single or dual for a low light setup. Ian, you recommend using 2 for this size then?


I'd say one would be ample if you are aiming for a low light setup.



dansmith said:


> So do you think a tank length of 110cm is pushing it as far as two grobeams are concerned?


I think that would work, assuming you put then inline with one another, if that makes sense?

I recall being told that one of the grobeam 600s has similar level of light output as one and a half T5 tubes when running at 100% output, which should help in deciding what people need for their setup.  Intensity can of course be adjusted by raising the unit, but I think the controller and the way it allows you to fade in and out of the photo period is what makes this lighting great to use.

Hope this helps.


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## GillesF (11 Jun 2013)

Excellent, thanks. I'll be getting one then!

Cheers,
Gilles


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## dansmith (12 Jun 2013)

Reuben said:


> Hello
> 
> 
> Well I think Ian's setup would be classed as high light as he had them running at max output for his photo period (we was actually using the grobeam 500s I think?) I've been faffing about and getting advice on here looking to make life easier by lowering output -just so I can make sure my Co2 and ferts are sufficient. Yes, i am using a TMC aquaray controller. I currently have this set for max out put from the two tubes as 20%. The controller also allows you to set on off times and has a ramp facility which lets you fade in and out the light. I have mine set to fade in out over 180 mins. This is nice as the light in the tank continually changes.
> ...


 When you say inline , I guess this is another term for head to tail, which is what I had in mind. I think the other way would be called parallel or even side by side. Love these technical terms. Thanks, anyway, I guess I just wanted a bit of reassurance that my idea was not stupid. So twin grobeam 600's it is. Oh and controller.


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## dansmith (12 Jun 2013)

Reuben said:


> Hello
> 
> 
> Well I think Ian's setup would be classed as high light as he had them running at max output for his photo period (we was actually using the grobeam 500s I think?) I've been faffing about and getting advice on here looking to make life easier by lowering output -just so I can make sure my Co2 and ferts are sufficient. Yes, i am using a TMC aquaray controller. I currently have this set for max out put from the two tubes as 20%. The controller also allows you to set on off times and has a ramp facility which lets you fade in and out the light. I have mine set to fade in out over 180 mins. This is nice as the light in the tank continually changes.
> ...


My uncle has the 1500 tile and runs it about 80% on a high light 20" cube , so I guess 20% is low , I know the tile has the same amount of leds as twin 600;s but it will not look the same on 20%, as the tiles leds are all concentrate and the 600;s have them strung out over their length. But if that is what it take to be low light then so be it. I suppose it is better to have too much light and to be able to dim it, than not (like t5's).


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