What's the deal with lighting?

[Era101]

Hi TFF,

I am hoping that you guys can help me out with lighting. I honestly don't get how it works and to know if you have a strong enough light for your plants.

I have been looking around and doing some research and the most common term I found was watt per gallon. Apparently you should aim for 2 to 5 watt per gallon (W/G), with probably 2 W/G being low light and 5 W/G being high. This I still get, but at some point people are debating what kind of lights to get and the benefits of those respective lights. Like LED, tradional, UV etc. I got really confused when they mentioned that one of the benefits of LED lights is that they consume less power. Does that mean LED lights need lower W/G than a tradional or UV light? If so, how do I calculate W/G for each respective light type?

 

[utahfish]

Hi TFF,

I am hoping that you guys can help me out with lighting. I honestly don't get how it works and to know if you have a strong enough light for your plants.

I have been looking around and doing some research and the most common term I found was watt per gallon. Apparently you should aim for 2 to 5 watt per gallon (W/G), with probably 2 W/G being low light and 5 W/G being high. This I still get, but at some point people are debating what kind of lights to get and the benefits of those respective lights. Like LED, tradional, UV etc. I got really confused when they mentioned that one of the benefits of LED lights is that they consume less power. Does that mean LED lights need lower W/G than a tradional or UV light? If so, how do I calculate W/G for each respective light type?

watts/ gallon is a bit outdated especially with the advent of LED. Whats more important is lumens and spectrum.
Plants do best with light that replicates natural sunlight or full spectrum lighting. Spectrum is expressed in K for Kelvin rating. K rating between 5000K and 6700K are full spectrum. As far as lumens go 10 to 20 lumens/ liter is considered low light plants, 30-40 medium light and 40 and above high light for hard to grow red and carpeting plants. Example if one has a light with 600 lumens over 75 liters( 20 US gallons) thats only about 8 lumens per liter which is really only good for growing algae. Shoot for at least 20 lumens per liter with a light between 5000k to 6700k with 6500k to 6700k being optimal. Good luck.

 

[mbsqw1d]

Yes with LED lighting, the wattage per gallon recommendation went out of the window because LED systems are so diverse, a one rule for all doesn't work as it did with older traditional incandescent and florescent setups.
LED lights tend to be bright enough (so long as your tank isn't abnormally deep), however the angle of light and colour spectrum are the areas of concern.
6500K is the spectrum you want to be looking for.

 

[Era101]

watts/ gallon is a bit outdated especially with the advent of LED. Whats more important is lumens and spectrum.
Plants do best with light that replicates natural sunlight or full spectrum lighting. Spectrum is expressed in K for Kelvin rating. K rating between 5000K and 6700K are full spectrum. As far as lumens go 10 to 20 lumens/ liter is considered low light plants, 30-40 medium light and 40 and above high light for hard to grow red and carpeting plants. Example if one has a light with 600 lumens over 75 liters( 20 US gallons) thats only about 8 lumens per liter which is really only good for growing algae. Shoot for at least 20 lumens per liter with a light between 5000k to 6700k with 6500k to 6700k being optimal. Good luck.

Aah, then I might have a problem.. I currently have a Kandilla S600 LED light. Not sure if they exist outside of Asia btw.

It's a 108 bulb of which 36 are colored, 12 red, 12 green and 12 blue. It's a 10,000 kelvin light though, which is kind of the standard here as well. I don't think I've really ever seen anything other 10,000 K lights except DIY lights or the crazy expensive ones. The box also doesn't show how much lumen the lights are, only that they are twice as bright as the previous model. How can I find out how much lumen the light gives?

 

[Era101]

Yes with LED lighting, the wattage per gallon recommendation went out of the window because LED systems are so diverse, a one rule for all doesn't work as it did with older traditional incandescent and florescent setups.
LED lights tend to be bright enough (so long as your tank isn't abnormally deep), however the angle of light and colour spectrum are the areas of concern.
6500K is the spectrum you want to be looking for.

What do you mean by angle of light and color spectrum?

 

[utahfish]

Aah, then I might have a problem.. I currently have a Kandilla S600 LED light. Not sure if they exist outside of Asia btw.

It's a 108 bulb of which 36 are colored, 12 red, 12 green and 12 blue. It's a 10,000 kelvin light though, which is kind of the standard here as well. I don't think I've really ever seen anything other 10,000 K lights except DIY lights or the crazy expensive ones. The box also doesn't show how much lumen the lights are, only that they are twice as bright as the previous model. How can I find out how much lumen the light gives?

10,000k is good for marine tanks and growing coral but lacks red and green light in it that plants need Plants mostly utilize RGB red green and blue. The higher K rating like 10,000 K the more blue and white light. A lower K rating like 4000K will have less blue and more red. Full spectrum between 5000K and 6700K will have a good level of blue and red light.
Having said that interesting it says its 10,000 K when its a RGB LED set up??? Must be because the remaining bulbs are white?
As far as lumens go see if you can find the manufacture specs on line or can call customer service and ask them.

 

[utahfish]

What do you mean by angle of light and color spectrum?

Color spectrum is the same as Kelvin rating.

 

[Era101]

10,000k is good for marine tanks and growing coral but lacks red and green light in it that plants need Plants mostly utilize RGB red green and blue. The higher K rating like 10,000 K the more blue and white light. A lower K rating like 4000K will have less blue and more red. Full spectrum between 5000K and 6700K will have a good level of blue and red light.
Having said that interesting it says its 10,000 K when its a RGB LED set up??? Must be because the remaining bulbs are white?
As far as lumens go see if you can find the manufacture specs on line or can call customer service and ask them.

I wouldn't know, maybe the white bulbs are 10,000K? Those are atill the most dominant bulbs, 72 white bulbs vs the 36 colored ones. Is it normally not the case that lighting with red, blue and green next to the white bulbs are 10,000K?

It's one of those products that have a manufacturing line and sell products all overasia but are impossible to find online and are without CS number. It's really common here to have brands and products like these.

 

[Era101]

Color spectrum is the same as Kelvin rating.

And angle of light? Just where the lamp is placed and at which angle the light falls on the plants?

 

[utahfish]

And angle of light? Just where the lamp is placed and at which angle the light falls on the plants?

Im not sure about angle of light. Directly above is most common

 

[utahfish]

I wouldn't know, maybe the white bulbs are 10,000K? Those are atill the most dominant bulbs, 72 white bulbs vs the 36 colored ones. Is it normally not the case that lighting with red, blue and green next to the white bulbs are 10,000K?

It's one of those products that have a manufacturing line and sell products all overasia but are impossible to find online and are without CS number. It's really common here to have brands and products like these.

Yeah the white bulbs are 10,000 k
I wouldnt worry too much as it will still grow plants with the RGB bulbs.
Yeah i tried looking up your light online couldnt find it. If there is a number on the box or a website call or go there and ask about lumens.

 

[Era101]

Yeah the white bulbs are 10,000 k
I wouldnt worry too much as it will still grow plants with the RGB bulbs.
Yeah i tried looking up your light online couldnt find it. If there is a number on the box or a website call or go there and ask about lumens.

Haven't been able to find any contact info whatsoever. So that's probably not going to work. I need a new lamp anyway, my red plants are slowly turning green again.
Just wanted to check if I really should just focus on the watts or if any other factors played a part. Do you maybe have a recommendation for a good lamp to use on a 60 cm 20 gallon tank? Preferably not too expensive.

 

[utahfish]

Haven't been able to find any contact info whatsoever. So that's probably not going to work. I need a new lamp anyway, my red plants are slowly turning green again.
Just wanted to check if I really should just focus on the watts or if any other factors played a part. Do you maybe have a recommendation for a good lamp to use on a 60 cm 20 gallon tank? Preferably not too expensive.

I actually use CFL bulbs in just regular clamp on desk lamp. I have a 20 gallon tank i use 4 bulbs 6500 K bulbs at about 600 lumens each for 2400 lumens which gives me a little over 30 lumens per liter.
If one can find CFL bulbs theyre relatively inexpensive. I got a 4 pack of bulbs for around 20.00$ each clamp lamp was about 5 bucks so the whole set up for 2400 lumens was about 40 bucks. You can hang the lights clamp them on back of tank with a goose neck clamp or lay they on top of glass top which is what i do.

 

[utahfish]

 

[utahfish]

If a cfl setup wouldnt work ive seen lots of people use all sorts of lights like shop lights flood lights for outdoor use whatever as long as the k rating is 5000K to 6700k daylight rated and provides enough lumens your good.
With red plants its not so much about light as it is CO2 and high light. Most red plants need high light and without CO2 that high light can grow algae instead of red plants.