Lighting a Planted Tank

convict360

Potamotrygon
MFK Member
Dec 9, 2013
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I've been looking into overhead LED light fixtures, and wondered if i could bounce a few ideas around.

The tank in question is 43 inch length, 11 inch width, and 11 inch in height (water level is always roughly 8 inches).

Am I right in assuming that should I want to go down the CO2 planted tank route, that I'm looking for something around 20,000 lumens? That would give me a level of 285, based on the calculation of:

(8x2) = 16 16 + 11 + 43 = 70

I'd seen some pretty cool LED fixtures, but these indicated a lumen level of 3415, which using the equation puts me at a level of 48. Does that mean that even with CO2 injection, some of the more advanced plant types will basically fail to establish?

I'd assume yes? I'm a noob to the lighting and planted tank game though, would appreciate some help
 

xxUnRaTeDxxRkOxx

Candiru
MFK Member
Jul 10, 2011
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Denver, CO.
While lumens is a bit helpful when selecting the right lighting, however aquarium lighting is mainly based on PAR now... Because planted tank lighting when going by lumens it doesn't specify how good the "bulbs" are at growing plants, Photosynthetically active radiation, often abbreviated PAR, designates the spectral range (wave band) of solar radiation from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of photosynthesis.

Also understanding chlorophyll peaks in plants will help you in selecting the best lighting for your planted aquarium, there's 2 stages of chlorophyll; Chlorophyll A and Chlorophyll B, each one peaks at different wavelengths. This chart will help to understand...


By selecting the best "bulbs" to correlate with the peaks in chlorophyll you'll find success!

This is the reason I prefer T5HO quad fixtures for planted tanks, it allows you to use multiple bulbs that target the peaks in the chlorophyll. Here's my all time favorite bulb for T5HO...


As you can see the WavePoint Ultra Growth Wave bulb specifically targets the peaks in chlorophyll a & b, which gives you the best growth in plants.
 
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Manu8__too

Aimara
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Jun 18, 2013
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While lumens is a bit helpful when selecting the right lighting, however aquarium lighting is mainly based on PAR now... Because planted tank lighting when going by lumens it doesn't specify how good the "bulbs" are at growing plants, Photosynthetically active radiation, often abbreviated PAR, designates the spectral range (wave band) of solar radiation from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of photosynthesis.

Also understanding chlorophyll peaks in plants will help you in selecting the best lighting for your planted aquarium, there's 2 stages of chlorophyll; Chlorophyll A and Chlorophyll B, each one peaks at different wavelengths. This chart will help to understand...


By selecting the best "bulbs" to correlate with the peaks in chlorophyll you'll find success!

This is the reason I prefer T5HO quad fixtures for planted tanks, it allows you to use multiple bulbs that target the peaks in the chlorophyll. Here's my all time favorite bulb for T5HO...


As you can see the WavePoint Ultra Growth Wave bulb specifically targets the peaks in chlorophyll a & b, which gives you the best growth in plants.
While I agree T5HO is an efficient and affordable way to go, a quad fixture is unecessary. With a 4 bulb fixture, he'll have to run incredibly high levels of Co2 with a tank that's 11" deep. A dual T5HO on that tank will require heavy Co2 alone. My T5HO (dual fixture) is 18" above the substrate and puts out around 80-100 PAR. A quad fixture would be absolutely insane.
 

xxUnRaTeDxxRkOxx

Candiru
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Jul 10, 2011
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I prefer T5HO quad systems because it allows me to use a specific lighting schedule... I like the Odyssea T5HO quad systems because they're cheap, and have a semi efficient reflector in them plus I use a specific set of bulbs in them.

Front bulb is a 6500k
2nd bulb is a 420nm actinic
3rd bulb is a 12,000k 460nm White actinic
4th bulb is a WavePoint Ultra Growth Wave

8am 2 front bulbs turn on
10am 2 rear bulbs turn on
2pm 2 front bulbs shut off
4pm 2 rear bulbs shut off

This lighting schedule gives me a 4 hour burst of light to simulate high noon sunlight... With the listed bulbs it hits the peaks in a plants chlorophyll stages, and gives me optimum healthy growth in the plants. With an automated Co2 system, I use a digital timer to program the co2 to turn on 1 hour before any of the light turn on, and then the co2 shuts off 1 hour before the final lights shut off.

I use a Rex Grigg's inline co2 reactor connected to a canister filter, with the filter out flow connected to the top of the co2 reactor, then connect the bottom of the reactor to the "out flow" nozzle in the tank. This gives me nearly 100% co2 absorption in the water. This is what works for me, but may not work for someone else...
 

tiger15

Goliath Tigerfish
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Oct 1, 2012
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Does any one knows how the lumen rule in post #1 is based on? It appears to be more reasonable than the old watt per gal rule given that lights come in many types and variety today. LED light is getting cheaper, more efficient, last longer, and have more variety to choose from, and LED is likely the future for planted tank and everything else.

I know PAR provides most accurate measurement for plant needs, but it is not a practical yardstick because manufacturers do not label their products with PAR. So consumers will have to rely on published watt, lumen and K values to select products.
Thanks for Chinese import. As posted in my other thread, there are many inexpensive led lights from Ebay to choose from:

https://www.monsterfishkeepers.com/forums/threads/plant-lights-for-tall-tank.685297/#post-7717745

When selecting light, pay attention to the lumen rating. I notice that many products are described as high lumen, but the rating shows otherwise with low numerical lumen rating. My new planted 75 set up has a total 7896 lumens which include one strip LED on top, and 3 submersible LED tied to the front and side rims. By surrounding the light on top, front and sides of my tank, I can get more even coverage given that LED is strongly directional. The combined light is very bright to me, but the formula only gives a rating of 7896 / (40+48+18+18) = 64 which puts my tank into low light plant regime. I am new in planted tank, and time will tell if my low light plants will thrive. I have no plan to go into high light regime as fish is my focus and too bright light may irritate the fish and doesn't look natural either.
 

viejafish

Plecostomus
MFK Member
Jan 31, 2013
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By selecting the best "bulbs" to correlate with the peaks in chlorophyll you'll find success!

This is the reason I prefer T5HO quad fixtures for planted tanks, it allows you to use multiple bulbs that target the peaks in the chlorophyll. Here's my all time favorite bulb for T5HO...


As you can see the WavePoint Ultra Growth Wave bulb specifically targets the peaks in chlorophyll a & b, which gives you the best growth in plants.
Selecting light to optimize coverage of photosynthetic wave lengths may be exaggerated out of reality by hobbyists and manufacturers. According to Diana Walstad in her classic book on Ecology of the Planted Aquarium, she cited an experiment comparing different florescent light bulbs revealed that, to her surprise, cool white bulbs perform equal to or better than full spectrum bulbs that provide more blue and red coverage. Her explanation is copied below:
upload_2017-4-9_8-6-21.png

upload_2017-4-9_7-46-16.png

The PAR theory is based on research data on terrestrial plants which may not be relevant to aquatic plants which have evolved to utilize other spectrum of light. So buying those expensive wavelength specific light bulbs may be over killed with no proven advantage.
 
Last edited:

xxUnRaTeDxxRkOxx

Candiru
MFK Member
Jul 10, 2011
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Denver, CO.
The term "cool white" when it comes to lighting is commonly used for bulbs from 5000k to 8000k... A commonly used bulb for planted tanks is a 6500k bulb that provides the following wavelengths...



So as you can see, a 6500k bulb produces wavelengths that mainly correspond with a plants chlorophyll stages.
 

Aqua Nut

Jack Dempsey
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Oct 15, 2016
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I don't really go by them charts as a lot more is in play here. My par on my 35 gallon tank is in the upper190 to 200 umol/m2/s with no algae and no co2. running for a year now. You cant go by chart like i said, it is a rule of thumb but more factors are in play like WC cycle, tank cleanliness, amount of stock as well as how much food you feed, water circulation, fertilizer and it goes on.. I have had no issues maintaining my tank. and keeping it algae free.
 
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