Inexpensive lighting for 125gal?

Hello, I'm planning on building a canopy for my 125gal sunfish aquarium. I would like to add some lighting, but I have no clue about lighting. I would like to set up some lights that are inexpensive, and that I can grow plants other than elodea, and that will brighten up my aquarium nice and clear

Plants eat light, which is to say they use chlorophyll and other chemicals to absorb light. They cannot absorb all colors of light, only blue and red. They reflect green. Here is a picture that shows the absorption spectrum of chlorophyll so you can see for yourself:
http://upload.wikime..._spectra-en.svg

Because plants cannot eat all colors of light, this means the light bulb that you get can't just produce any old color of light. A good plant light produces a lot of red and blue. But how do you know what colors of light your bulb is emitting? All light bulbs just look white. The answer is to use an inexpensive diffractometer grating. They are only $5 online. Here is a video showing you how to use one:
http://www.youtube.com/watch?v=c44-iiINuVE

You don't actually have to buy one of those; just realize that not all white light is created equal. Some white light has only three values of wavelength, for example one blue peak, one green peak, and one red peak. Other white light has a continuous emission spectrum and emits high values all along the spectrum. Here is an example image that demonstrates some different light bulbs' emissions: http://housecraft.ca..._responses2.png

The plots above show light intensity on the y axis and shade of light color or 'wavelength' on the x axis. You can see daylight in the upper left. Daylight has high y values for every value of x. There is a flourescent bulb in the upper right and a warm white LED in the bottom right that have high green values but very low blue and red values. All three of these lights probably look like white light but only daylight, with the high values in blue and red, would grow plants well. We can spot one other light that would likely grow plants well based upon its emission spectrum: the cool white LED that has a large blue peak. In general the more blue in the light, the better it grows plants. Green colored plants reflect green light and absorb blue and red. Red colored plants reflect both green and red light and only absorb blue light. So if you want to be able to grow all of the colors of plants, blue light is usually a safe bet.

What does this information mean for you practically? It means you don't have to spend all the super bucks on a specialty 'plant light'. Now that you have the information that blue light grows plants really well, and red light grows green plants but not red plants, and green light grows neither, you can make your own well informed lighting decisions and you just might save some money.
For example, I took some pictures of my lights through the diffraction grating of my digital camera. Here's the result: http://forum.aquatic...file.php?id=419 You can see the rest of the story here: http://forum.aquatic...=1429&start=105 Basically the idea is, by knowing that a lot of the light's emitted color was blue and red, I knew the light would grow plants well. yay, success.

Now that you know that your light bulb should make a lot of blue and red light, which light bulb should you / can you pick that costs the least amount of money, both in initial purchase and in operating cost? There are four major types of light bulb:
1. Incandescent. A tungsten filament heats up and produces light. Pro: first discovered light bulb. Con: Mostly makes heat, not light. Around 20 lumens of light produced per watt of energy.
2. Flourescent. Electrons are excited, and when they fall back down into their lower energy they release light. Pro: Inexpensive due to is mass use in office overhead lighting, makes much more light and less heat than incandescent lights using the same amount of energy. Can be removed and replaced, and, Con: should be replaced about once a year (the light color decays over time). Around 60 lumens of light per watt of energy.
3. LED. Electrons recombine with holes across the band gap of a semiconductor, emitting light. Pro: More light less heat. Con: Used to be prohibitively expensive. Also when they burn out they burn out. I haven't figured out yet how to replace my burned out ones that are all permanently adhered into the same fixture with working ones. If you find out, let me know. Around 90 lumens of light per watt of energy.
4. Metal halides. I don't really know how these work; I just know they start at 300 bucks a fixture so they're out of my price range. They make a lot of light though. Around 100 lumens of light per watt of energy. I give the sources for all those lumen claims here: http://forum.nanfa.o...k-construction/



My standard lighting suggestion for four foot long tanks is four Daylight Deluxe bulbs ($10 for two at Home Depot) in a $10 Walmart four foot long T8 fixture. 'Full spectrum' bulbs like the daylight deluxes emit a wide smear of colors, plenty of red and blue, and they grow plants well. I just don't like their K value all too much. 6500 K looks a bit yellow, whereas 10,000 K is a lot more blue-white. This picture explains it better than I can: http://upload.wikime...-comparison.png
Recently I figured out that if you add a $7.50 blue LED light strip to the 6500 K bulbs you can make the K value a lot closer to pretty without having to drop $100 on a T5HO fixture. Video explanation: http://www.youtube.com/watch?v=eS2iOfuNx_U
So for $40 in flourescent light (two $10 fixtures, two $10 packs of bulbs) and $7.50 in a blue LED strip, I made a fairly pretty looking tank that grows plants well. Eh, honestly I could have just replaced the flourescent bulbs, which were only yellow in color due to age, for $20 of new bulbs, and fixed the problem without using an LED. The new bulbs are much less yellow. But I was kinda curious about LED strips, so.

In general I find that 8 to 10 hours a day of 100 lumens/gallon of full spectrum or red and blue rich light grows plants well. I recommend you buy a timer so your lights turn on and off at set time points during the day. If you've got cladophora algae growing a lot you can reduce the number of hours per day and it won't grow as much.

You can use this knowledge of what the plants need from the light (red and blue light) to make informed decisions about what light you want to pay money for.

Edited by EricaWieser, 08 May 2013 - 09:19 PM.

Thank you!!! Wow, that was a lot of information My aquarium is about 6 feet long, and the main light fixtures i found were the 4 feet long ones. So I'll probably not go for that, unless I get a 4 foot long aquarium.
I have a 30inch aquarium light fixture that came with my 125gal. Although its a single bulb, do you think if I get another 30inch light fixture(30inch light on left side of aquarium and 30inch on the right), would it be enough light? And so, which bulbs would you recommend, I was looking through the ones they had for sale on Fosters and Smiths, the 18,000K(aqua-glo) caught my attention http://www.drsfoster...fm?pcatid=12763
It has a lot of blue light and since its at 18,000k would that mean it would look more blue-white?

which bulbs would you recommend, I was looking through the ones they had for sale on Fosters and Smiths, the 18,000K(aqua-glo) caught my attention http://www.drsfoster...fm?pcatid=12763

The website didn't list the lumens so I googled the bulb and found it on ebay.
Link: http://www.amazon.co...t/dp/B0002AQLS8
It appears to only emit 900 lumens. Two 900 lumen bulbs would be 900 * 2 = 1800 lumens in a 125 gallon tank.
1800 lumens / 125 gallons = 14.4 lumens per gallon, about one tenth of my recommended 100 lumens per gallon.
Conclusion: that is not bright enough to grow plants.

There are many places to find inexpensive aquarium lighting. Ebay has some really good deals. Aquatraders.com has a large lighting section. And local hardware stores make shop lights that are intended for garages and under cabinets that work well for fish tanks.

You could cut a sheet of plexiglass ($5 at your local hardware store) to make a waterproof tank lid. Then you could rest whatever lights you want on top of it without having to worry about fish jumping out.

Edited by EricaWieser, 09 May 2013 - 12:58 AM.

I make my own light fixtures and recently switched to T5 bulbs for the efficiency. What surprised me most was that they were brighter than the old T12's, by a good margin! I never had a green thumb when it comes to aquarium plants, but now I'm actually growing hornwort and amazon swords in a tank. Again, I'm not a plant expert, so I consider this a HUGE improvement! LOL I'm using cool white bulbs, nothing special. If I were to light a 125 for plants I would use four 36" T5's. The 2 front bulbs would be "aquarium" type bulbs to bring out the fishes colors and the back 2 bulbs cool white.

As for plexiglass aquarium lids, I'm sorry to say don't waste your money. The plexi will warp with temperature difference and the corners won't seat well. My purpose for aquarium lids isn't just to keep fish in, but to minimize evaporation too. Also, over time the plexi will "craze", which is many small cracks. I recommend going to a local glass shop and having a top made to your dimensions. #1 it's much cheeper than a ready made top. #2 even with custom cutting (holes, corners, edges) it's cheeper than a ready made top. #3 it's good for the local economy. #4 it just doesn't warp!

I can cut my own glass tops when I have the glass, but it's not so totally expensive to have a glass shop do it either.

The website didn't list the lumens so I googled the bulb and found it on ebay.
Link: http://www.amazon.co...t/dp/B0002AQLS8
It appears to only emit 900 lumens. Two 900 lumen bulbs would be 900 * 2 = 1800 lumens in a 125 gallon tank.
1800 lumens / 125 gallons = 14.4 lumens per gallon, about one tenth of my recommended 100 lumens per gallon.
Conclusion: that is not bright enough to grow plants.

There are many places to find inexpensive aquarium lighting. Ebay has some really good deals. Aquatraders.com has a large lighting section. And local hardware stores make shop lights that are intended for garages and under cabinets that work well for fish tanks.

You could cut a sheet of plexiglass ($5 at your local hardware store) to make a waterproof tank lid. Then you could rest whatever lights you want on top of it without having to worry about fish jumping out.

Make certain you space your lights high enough from that plexiglas. Any heat output will cause the plexiglas to soften and/or catch fire!

My apologies. Glass seems to be the way to go. I have no personal experience using either plexiglass or glass. My fish and invertebrates haven't jumped out ever since I started covering the surface of the water with live plants to protect fry. I'm able to get away with just resting the lights right on top of the water like this:
http://img.photobuck...imiru/018-4.jpg
http://img.photobuck...imiru/016-4.jpg
http://img.photobuck...imiru/015-3.jpg
http://img.photobuck...imiru/005-3.jpg

Thank you!!! Wow, that was a lot of information My aquarium is about 6 feet long, and the main light fixtures i found were the 4 feet long ones. So I'll probably not go for that, unless I get a 4 foot long aquarium.
I have a 30inch aquarium light fixture that came with my 125gal. Although its a single bulb, do you think if I get another 30inch light fixture(30inch light on left side of aquarium and 30inch on the right), would it be enough light? And so, which bulbs would you recommend, I was looking through the ones they had for sale on Fosters and Smiths, the 18,000K(aqua-glo) caught my attention http://www.drsfoster...fm?pcatid=12763
It has a lot of blue light and since its at 18,000k would that mean it would look more blue-white?

I have a 6ft tank, and I use the 4ft 'shop' lights from Lowes. It puts plenty enough light in the tank, but then again, I don't grow plants.

I read on another forum a few years back that if you put your lights on top of glass, it takes away from the full power of the bulb and to only cover the areas around the light fixture with glass but not underneath it. does anyone know if this is true?

I read on another forum a few years back that if you put your lights on top of glass, it takes away from the full power of the bulb and to only cover the areas around the light fixture with glass but not underneath it. does anyone know if this is true?

I no longer use glass on any of my aquariums and see no difference between using it and not, except:

• Without glass, the fixtures on my saltwater tanks rust really fast. This isn't an issue on my freshwater tanks. I have lights that have been on my freshwater tanks for more than five years with no sign of rust. On the saltwater setup they showed rust in less than one year.
• Sometimes if the light is too short for the tank it can fall in. This would have been a problem with the 18" inch lights on my 20" 10 gallon tank, but I used packing tape to make a ledge to set the light on. One of my tanks, a 10 gallon, now has a Home Depot $8 clamp light and a more than 1000 lumen compact fluorescent bulb in it (one of my favorite setups, the bulbs were $10 for four and are very bright). The clamp light shines diagonally instead of down when clamped on the tank, so I bought a thin sheet of acrylic or polycarbonate or plexiglass, I can't remember which but it was the most rigid one, then set that on my tank and set my light on it. I keep it clean without old plant debris or salt drying on it, so I see no reduction in light brightness.

Hello again, everybody. In the time since this topic was originally posted in May, I've become less of a fan of the LED strip lights. They aren't as waterproof as they claim and mine broke within a month or two. Also, it turns out that my water was only really yellow because the mulch in the substrate was releasing a lot of tannins. The bulbs weren't themselves yellow. D'oh. So with more frequent water changes (and possibly the use of some activated carbon or seachem purigen), the water is crystal clear and I'm finding 6500 K to be quite a tolerable color. I also found T8 bulb covers on ebay for $7 each. They come in different colors, one of them being blue. This allows me to turn any white T8 bulb into an 'actinic' by putting it inside a blue bulb cover. And the nice thing about bulb covers instead of paying more for a blue bulb is that if/when the bulb burns out, you can just put the bulb cover on a fresh white bulb. The Daylight Deluxe bulbs are 2750 lumen each and has quite a high blue peak, so even if the blue bulb cover is blocking out the other colors, there are still plenty of lumens getting through. It's a nice inexpensive solution to the lack of T8 actinic bulbs being sold on the market.

I also feel the need to address PAR here. First, here's a link to an educational article from a person who really likes PAR: http://www.buildmyled.com/about-par/

And now here's my response:
It would be great if PPF and PPFD were listed on bulb boxes. But they're not. All the box is gonna tell you you are length of bulb, number of watts it maximum can handle, lumens, and type of bulb. Of those, the lumens is the only number that gives us any idea about how much light the bulb will make. Watts isn't a good thing to look at because different bulbs make different lumens of light from the same number of watts depending on their efficiency. So we're left with what we have to work with, which is lumens. Would I prefer it if each bulb told me its photons? Yes! I would love that. Lumens, it turns out, aren't equal across the visible spectrum; green light waves look brighter to our eyes than red so the same number of green versus red waves gets a slightly higher lumen rating. So it's not a perfect unit of measurement, true. But since it's the one that everyone uses, that's what we have to work with. And it turns out it works just fine. I've found that 100 to 200 lumens of blue and red rich light (use a diffraction grating to make sure the bulb's making a wide smear of colors, not just a few sharp peaks, or buy a bulb that's labeled 'full spectrum') work great to grow plants. Below 100 lumens per gallon, plants don't grow well. Over 200 and too much algae grows. Using lumens as your measurement opens up a whole world of bulb options. Now you can shop for a light for your fish tank not only among aquarium bulbs but in the entire bulb market: shop lights, office lighting, spot lights, the world is your oyster.

Oh, also, I forgot to say that I went on a CREE LED research kick a while ago and there are totally 10,000 K (pretty shade of light) flood lights that would light a 125 gallon for < $200 on ebay.

Oh nice do you have the link?

Oh nice do you have the link?

First some quick math to see how many lumens you need. If 100 to 200 lumens per gallon works well to grow plants, let's say 150 is a good number. You'll want 150 * 125 gallons in your tank = 18,750 lumens. Let's round and say 20,000 lumens.

It's going to take some googling to find the least expensive one, but in general a cursory search can find things like this:

• $290: http://www.ebay.com/...a2adc8c&vxp=mtr "37" 200W Spot/Flood/Combo Work Light CREE LED Offroad Driving Lamp Pickup 12 24v"
• $200: http://www.ebay.com/...=item5af5560607 "eLight High Bay Fluorescent Light Fixture- 4-Lamp T5 Light 20,000 Lumens #6210"
• $60: http://www.ebay.com/...=item5d4404082a "CCI 2-In-1 Twin Head Tripod Halogen Power Light- 1,200 Watts 20,000 Lumens #L19"
• >$50 You could hook up 10 of these. http://www.ebay.com/...=item43bf1cc445 "CFL Energy Saving 32W=125 Watt Compact Fluorescent Grow Light Bulb 2100 Lumens" Either put them in your own custom made fixture or buy a few of these Home Depot clamp lights (probably available somewhere online in bulk): http://www.homedepot...11#.UjtNp8akpYU You'd only need 7 if you used these: http://www.amazon.co...n/dp/B003BFTR14

Number 3 on that list is quite tempting. Just point a spotlight at it, done. Easy, cheap, effective.

That was just a reeeeeally brief search, so I'm sure if you looked around a bit more you'd find things for less. I've got one of those compact fluorescent bulbs over one of my tanks now and Wow! They are bright. When they start listing a number above 1,000 lumens for a compact bulb, that's code for Don't look directly at it. lol modern technology is awesome

I don't think a blue cover is helping your plants. All you're doing is absorbing non-blue light, not increasing the amount of blue available.

I don't think a blue cover is helping your plants. All you're doing is absorbing non-blue light, not increasing the amount of blue available.

Nooooo, lol, it's not for the plants. It's for changing the k value color temperature of the light from 6500 to something closer to 10,000 or 20,000 K. Colors that commercial T8 bulbs aren't available in. One blue bulb out of four makes the whole overall light change shade.

Nooooo, lol, it's not for the plants. It's for changing the k value color temperature of the light from 6500 to something closer to 10,000 or 20,000 K. Colors that commercial T8 bulbs aren't available in. One blue bulb out of four makes the whole overall light change shade.

Here's a picture that might help with visualizing that.


http://www.mediacoll...temperature.gif

Adding a blue bulb will make the overall shade more blue. This can change a tank from 6500K to something closer to 10,000K. It's a subtle difference but since one of the major complaints I had about using T8 bulbs is nobody sells blue T8 bulbs, it means I enjoy my fish tank much more. I personally find 10,000K fish tank to be prettier than a 5000K tank. 6500 is okay but making one of the four bulbs blue makes me happier And actinic (AKA blue) bulbs make coral colors really pop

Here's the spectrum of daylight deluxe bulbs:

http://i138.photobuc...sF40DX6500K.jpg

More than half of their light was blue anyway so blocking out the other colors doesn't diminish the lumen output by that much. As I discussed in post #2, blue is the most useful color because it is the only light that both red and green plants can eat. They both reflect green and red plants also reflect red. So this is a pretty good bulb for plant growth.

And again, K value has nothing to do with what's in a bulb's spectrum. One large peak can completely overshadow all the rest so K value can't tell you if you've got a good wide smear of wavelengths (tasty to plants) or just three sharp peaks (potential for starvation). Thankfully most bulbs have their spectrums online so you can just google it. Or you can buy a diffraction grating for $5 on ebay and look manually the video in post #2 demonstrates.

i found a light at lowes that has 4 48" t8 bulbs in it. works pretty good.

while t8 actinics can be found online, they are EXPENSIVE!
its much easier to just go with shop lights, and they work pretty good.

i used to use t12s. even those were good enough for decent plant growth...
as you can see


i did have a tendency to go through the t12s fast. i think those setups were meant for t8s...

edit: forgot to mention, that pic was taken right after i switched over to t8s. shortly after that, the strips died(rusted) and i bought the quad bulb light. so, the growth was all under t12s, but what you are seeing is t8 light.

Edited by Auban, 12 October 2013 - 08:15 PM.

I've been telling other people about this post and someone responded with this:

Green Light Drives Leaf Photosynthesis More Efficiently than Red Light in Strong White Light: Revisiting the Enigmatic Question of Why Leaves are Green
Ichiro Terashima1,*, Takashi Fujita1, Takeshi Inoue1, Wah Soon Chow2 and Riichi Oguchi1,2,3
+ Author Affiliations

1Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan
2Photobioenergetics Group, School of Biology, College of Medicine, Biology and Environment, The Australian National University, Canberra, ACT 0200, Australia
*Corresponding author: E-mail, itera@biol.s.u-tokyo.ac.jp; Fax, +81-3-5841-4465.
Received January 4, 2009.
Accepted February 24, 2009.


Abstract

The literature and our present examinations indicate that the intra-leaf light absorption profile is in most cases steeper than the photosynthetic capacity profile. In strong white light, therefore, the quantum yield of photosynthesis would be lower in the upper chloroplasts, located near the illuminated surface, than that in the lower chloroplasts. Because green light can penetrate further into the leaf than red or blue light, in strong white light, any additional green light absorbed by the lower chloroplasts would increase leaf photosynthesis to a greater extent than would additional red or blue light. Based on the assessment of effects of the additional monochromatic light on leaf photosynthesis, we developed the differential quantum yield method that quantifies efficiency of any monochromatic light in white light. Application of this method to sunflower leaves clearly showed that, in moderate to strong white light, green light drove photosynthesis more effectively than red light. The green leaf should have a considerable volume of chloroplasts to accommodate the inefficient carboxylation enzyme, Rubisco, and deliver appropriate light to all the chloroplasts. By using chlorophylls that absorb green light weakly, modifying mesophyll structure and adjusting the Rubisco/chlorophyll ratio, the leaf appears to satisfy two somewhat conflicting requirements: to increase the absorptance of photosynthetically active radiation, and to drive photosynthesis efficiently in all the chloroplasts. We also discuss some serious problems that are caused by neglecting these intra-leaf profiles when estimating whole leaf electron transport rates and assessing photoinhibition by fluorescence techniques.


My interpretation of the paper:
Plants' outer tissue layer layer reflects some green (making the plant look green to our eyes) and lets the rest of the green pass through to deeper tissue. Inner tissues can absorb the green that penetrates through the outer layer. Because of the ability of deeper tissue to absorb green light, it's possible that my very first post on here about red and blue being better plant foods isn't quite true. High intensity green that reaches the deeper tissues can also be eaten. So really this paper is saying that the most important thing to consider when setting up a light to grow aquarium plants is the light's brightness. Brightness has more to do with a light's ability to feed plants than the proportion of the light's spectrum that is blue or red. For us fishkeepers and aquarium plant growers, that means we can most easily guess at a light's ability to grow plants by the lumen rating on the bulb. (Bulbs are mysterious about their PAR ratings and other units of brightness. Lumens is the usually only number on the box describing its brightness.) The spectrum of red and blue and green has less to do with a bulb's food value to the plant than I'd previously thought. That's good news for us fishkeepers, since spectrum is basically never printed on the bulb's box.

My own personal experience actually agrees with this paper quite a bit. I'm finding more and more that bright lights (around 100 to 200 lumens per gallon) all seem to do the trick to grow plants well regardless of what bulb I use. I've used blue and red rich lights and I've used random lights that I didn't know the spectrum of, and somehow the plants haven't faltered. They're still growing great. It makes sense that in deep tissue, the plant pulls some funny tricks to absorb the green that's the only color that's passing through the outer layers. If it's there, eat it, right?

Some people might say, "But doesn't the light spectrum have to do with algae growth?" I don't know. I haven't seen algae since I first put my lights on a timer, 2 to 3 hours in the morning before work, 5 to 6 hours once I get home from work.