Lighting

[Gaz111]

Tank dimensions 900x52x54 I currently swapping from marines to tropical the light I currently have are evergrow 5018 with 6 channels red,green,white, blue, royal blues and uv which ramp up and down on a timer and I can set strength of each channel (gave back ground so you don’t need to google it )

I’d like a planted tank. I could sell these for say £200 or keep them and change it around to suit tropical

Can anyone recommend me a good light for my tank? Or do you think by the time I sell these buy another light I might as well keep the ones I have?

Im very indecisive at the moment

 

[Byron]

Can you change the diodes in the current fixture, and do they make planted tank diodes? This might be less expensive that a new unit. And the issue with the present light is that it will be high in the blue which promotes algae.

Aquatic plants require red and blue light to drive photosynthesis; the red is the more significant. High green added to the red and blue doe3s improve plant growth, probably because this is closest to mid-day sun under which the plants evolved. Marine tanks need very high blue, especially for corals. And most of the "basic" LED is high in blue as well. The red is usually minimal.

I use the Kelvin scale or CRI (colour rendering index) numbers. A Kelvin in the 5000K to 6500K range is ideal; a CRI as close to 100 is good.

A word on the white light...white light is a combination of wavelengths of colour, such as a rainbow or the spectrum. Light in the 5000K range will have more red in the mix for a warmer white, while the light in the 6500K range has a bit more blue for a cooler white--but it also has high red and green. This has to be the composition of the white light. Having red, blue, green and white diodes does not do it, the colours have to be incorporated into the white light (don't know how else to explain it).

 

[Gaz111]

Can you change the diodes in the current fixture, and do they make planted tank diodes? This might be less expensive that a new unit. And the issue with the present light is that it will be high in the blue which promotes algae.

Aquatic plants require red and blue light to drive photosynthesis; the red is the more significant. High green added to the red and blue doe3s improve plant growth, probably because this is closest to mid-day sun under which the plants evolved. Marine tanks need very high blue, especially for corals. And most of the "basic" LED is high in blue as well. The red is usually minimal.

I use the Kelvin scale or CRI (colour rendering index) numbers. A Kelvin in the 5000K to 6500K range is ideal; a CRI as close to 100 is good.

A word on the white light...white light is a combination of wavelengths of colour, such as a rainbow or the spectrum. Light in the 5000K range will have more red in the mix for a warmer white, while the light in the 6500K range has a bit more blue for a cooler white--but it also has high red and green. This has to be the composition of the white light. Having red, blue, green and white diodes does not do it, the colours have to be incorporated into the white light (don't know how else to explain it).

Thanks for the quick reply!

These are the 6 channels I have

• Hyper Red: 4 Osram (3W)
• Green: 4 Cree XPE (3W)
• Deep Blue: 16 Cree XTE (5W)
• Cool White: 20 Cree XTE (5W)
• Blue: 16 Cree XPE (3W)
• Indigo: 12 SemiLEDS (3W)

These are dimmable so I can set these to anything from off (0%) to 100% set by the hour. basically in the morning you start things off on like 5% and ramp up to 70% up to midday then ramp back down. So I could take out as much or little blue as needed.

Can’t seem to find any info on what kelvins the white light is on its own unfortunately but could I just use red,green and white? Maybe do a sunrise to sunset like I do for marine?

 

[Byron]

I am not familiar with LED except for the five units I did try and all went back because they were not sufficient/adequate. This light is for marine, and you can be assured it has too little red and too much blue. "Cool white" by the way is high blue low red, more of the same.

Using the individual colour diodes that I saw over a tank would not work for me. There were colour streaks down into the water from red, green, white. What you need is a mix of the red/blue/green in the white diodes.

 

[Uberhoust]

With your configuration I don't think you really can use color temperature for determination there are too many discrete frequency LEDs. Your white LEDs as are likely in the 5000 to 6500 kelvin range but the Cree XTE series has a number of possible "whites" from 2700 to 6500 degrees, datasheet for those found here https://cree-led.com/media/documents/XLampXTE.pdf, https://cree-led.com/media/documents/XLampXPE-25A.pdf.

The rest of the LED are specific wavelengths, with the Hyper Red at 660 nm which is right at the red absorption spectra value for chlorophyll a, and the Deep Blue Cree XTE is at the 460 nm which is at the blue side of the absorption spectra for chlorophyll b, the Blue Cree XPEs are only slightly longer wavelength about 470, covering the chlorophyll b and beta carotene absorptions. The green Cree xpe is at 530 nm which is on the red side for the b carotene. Could not find a data sheet for the Indigo SemiLEDs but I came upon a reference on a reef site that suggests that they are at 415 nm which would put them at peak for chlorophyll a absorption.

Overall your light seems like it would be fine for growing plants in a freshwater aquarium, but you may have to tune it to prevent excessive algae and also to balance the color you see, which in this case is what the white LEDs seem to be for. The discrete frequency choices on this light seem to be entirely engineered to grow plants. It might be low on the red, but otherwise the choice of LEDs make sense.

Overall you cannot use CRI and Color temperature for lamps with discrete frequencies, it is really only applicable to the various white lights where the colors produced match the frequency distribution on a black body object at a specific temperature.

 

[Gaz111]

With your configuration I don't think you really can use color temperature for determination there are too many discrete frequency LEDs. Your white LEDs as are likely in the 5000 to 6500 kelvin range but the Cree XTE series has a number of possible "whites" from 2700 to 6500 degrees, datasheet for those found here https://cree-led.com/media/documents/XLampXTE.pdf, https://cree-led.com/media/documents/XLampXPE-25A.pdf.

The rest of the LED are specific wavelengths, with the Hyper Red at 660 nm which is right at the red absorption spectra value for chlorophyll a, and the Deep Blue Cree XTE is at the 460 nm which is at the blue side of the absorption spectra for chlorophyll b, the Blue Cree XPEs are only slightly longer wavelength about 470, covering the chlorophyll b and beta carotene absorptions. The green Cree xpe is at 530 nm which is on the red side for the b carotene. Could not find a data sheet for the Indigo SemiLEDs but I came upon a reference on a reef site that suggests that they are at 415 nm which would put them at peak for chlorophyll a absorption.

Overall your light seems like it would be fine for growing plants in a freshwater aquarium, but you may have to tune it to prevent excessive algae and also to balance the color you see, which in this case is what the white LEDs seem to be for. The discrete frequency choices on this light seem to be entirely engineered to grow plants. It might be low on the red, but otherwise the choice of LEDs make sense.

Overall you cannot use CRI and Color temperature for lamps with discrete frequencies, it is really only applicable to the various white lights where the colors produced match the frequency distribution on a black body object at a specific temperature.

Thanks for the detailed post! One of the sites that sells them says it Can be used with any indoor growing method – hydroponics, aeroponics so must be ‘ok’ so what would be your advise be sell them or go for it and see how I go?

 

[Uberhoust]

In my opinion I would keep them and try them out. It is a balance of what looks good to you, and what works for the plants. I would suggest that they are a bit low on the red side but I didn't look at the luminosity, red LEDs are easier to make and might produce more lumens than the blue leds. Overall you currently own them, you can reduce their output for the tropical tank, meaning they will likely last longer, if they don't work out you can still replace them later.

 

[Gaz111]

In my opinion I would keep them and try them out. It is a balance of what looks good to you, and what works for the plants. I would suggest that they are a bit low on the red side but I didn't look at the luminosity, red LEDs are easier to make and might produce more lumens than the blue leds. Overall you currently own them, you can reduce their output for the tropical tank, meaning they will likely last longer, if they don't work out you can still replace them later.

Okay I’ll hold on to them for now I hate selling things!

 

[Colin_T]

Keep it and reduce the UV. See how the plants do for a few months. If you have to change it, you can but the sun provides the same light all over the world, albeit in different concentrations so a light for a marine tank, which is used to cultivate algae in corals, is normally fine for freshwater. However, you don't need the UV or as much blue in freshwater. But try it for a few months before you spend hundreds of dollars on a freshwtaer light unit because they are 6 of 1, half a dozen of the other.