I am using (2) 48" 2 bulb Flourescent light fixtures for a total of (4) 40 Watt bulbs on a standard 75 Gallon tank. Any advice on what bulbs to use (they take 48" T12 bulbs) for the best plant growth in a planted tank? My Compact flourescent fixture went bad and for cost reasons I went with the 2 shop lights. I currently have 2 cool whites and 2 soft whites in them and plant growth is reduced and algae is worse in a walstad type tank. I am guessing 160 watts should be OK so it must be the bulb type. Any suggestions would be greatly appreciated. The tank is up for almost 2 years with no problems until now.
Plant Lighting Help
Started by
Guest_mshi_*
, Dec 05 2008 02:20 PM
15 replies to this topic
#2
Guest_dafrimpster_*
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Posted 05 December 2008 - 03:15 PM
You can find 6500k T12 bulbs at Menard's or Lowes usually. this is within the light spectrum plants can use and I like the look of 6500k lighting.
On the algae issue, you have slightly more than 2wpg. You are beginning to enter the realm of needing CO2 and dosing ferts. Things may even out after time. I have 96w of T8 6500k on my 55g and it took a while to get enough plant mass to be able to compete with the algae for light and nutrients. I don't do ferts or CO2.
On the algae issue, you have slightly more than 2wpg. You are beginning to enter the realm of needing CO2 and dosing ferts. Things may even out after time. I have 96w of T8 6500k on my 55g and it took a while to get enough plant mass to be able to compete with the algae for light and nutrients. I don't do ferts or CO2.
#3
Guest_Newt_*
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Posted 05 December 2008 - 04:03 PM
I've found that adding macroalgae, such as Cladophora or Spirogyra, can help suppress the smaller green algae. I suppose they are more direct competitors for nutrients.
#4
Guest_nativeplanter_*
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Posted 05 December 2008 - 05:28 PM
There could be a few things going on. Here are some questions:
Has your nutrient load changed? More fish/different fish/feeding more/less?
How old is the soil?
What is your hardness?
I have found a few things over time: with continued harvesting, nutrients in the soil get depleted and plant growth is reduced or can look poor. I get around this by adding bits of Miracle Grow houseplant sticks directly at the base of the plants under the soil.
Some plants require a good deal of calcium. If your hardness is low, try throwing in a calcium tablet. Calcium can be reduced by harvesting, too.
If you are feeding differently, that would change the nutrient load in the water column.
Unfortunately, color temperature doesn't say a whole lot. Read this discussion we had a while ago here: http://forum.nanfa.o...?showtopic=4289
Cyanobacteria can use some light wavelengths that plants can not. Your new bulbs may have more in the 550-650nm range.
If you don't know the spectra of your bulbs and want to keep on the cheap, try replacing one of the warm whites with a cool white. Yes, this still relates more to color temperature than spectra, but you might reduce the 550-650nm red/orange. I wouldn't replace both warm whites with cool whites, some light in the 650-675nm range is beneficial, and will help keep the tank from looking to cold in my opinion. Doing this is a cheap way that just might work.
Has your nutrient load changed? More fish/different fish/feeding more/less?
How old is the soil?
What is your hardness?
I have found a few things over time: with continued harvesting, nutrients in the soil get depleted and plant growth is reduced or can look poor. I get around this by adding bits of Miracle Grow houseplant sticks directly at the base of the plants under the soil.
Some plants require a good deal of calcium. If your hardness is low, try throwing in a calcium tablet. Calcium can be reduced by harvesting, too.
If you are feeding differently, that would change the nutrient load in the water column.
Unfortunately, color temperature doesn't say a whole lot. Read this discussion we had a while ago here: http://forum.nanfa.o...?showtopic=4289
Cyanobacteria can use some light wavelengths that plants can not. Your new bulbs may have more in the 550-650nm range.
If you don't know the spectra of your bulbs and want to keep on the cheap, try replacing one of the warm whites with a cool white. Yes, this still relates more to color temperature than spectra, but you might reduce the 550-650nm red/orange. I wouldn't replace both warm whites with cool whites, some light in the 650-675nm range is beneficial, and will help keep the tank from looking to cold in my opinion. Doing this is a cheap way that just might work.
#5
Guest_Geoff03_*
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Posted 05 December 2008 - 08:04 PM
the WPG rule starts to get fuzzy after thr 55/60 gallon marker. it becomes less of a bench mark. the problem with shop lights is that they are ment for a shop, and lighting large opening areas, so you are getting alot of light spread out of your tank instead of directly into it. This can cause problems. a direct light of less power will have beter effects for plants then more light with less direction. shop lights can be used effectivly, but they require alittle work to make them good. you need to modifiy the reflector so that less light is spreading outward and more is getting focused downward.
here an experiment i did a while back, when i had my 55 gallon. previously i had 2 shop lights with 4 "40" watt bulbs ( they actually dont pull 40 watts but whatever ) and then i switched over to a fixture ment for aquariums and ran 4 28 watt T5 bulbs.
first is the shoplights:
notice how much light is spilling to the side and that you can count out almost to 5 tiles on the floor. thats alot of spilled light
now here are the t5's
notice how much more direct the light is. the light on the floor barely comes out 2 tiles. this focusing of light is the key to having an effective fixture. even with those lights plus some power compacts on my 75 i have about that same amount of light on the floor if not less. its pretty good deal.
here an experiment i did a while back, when i had my 55 gallon. previously i had 2 shop lights with 4 "40" watt bulbs ( they actually dont pull 40 watts but whatever ) and then i switched over to a fixture ment for aquariums and ran 4 28 watt T5 bulbs.
first is the shoplights:
notice how much light is spilling to the side and that you can count out almost to 5 tiles on the floor. thats alot of spilled light
now here are the t5's
notice how much more direct the light is. the light on the floor barely comes out 2 tiles. this focusing of light is the key to having an effective fixture. even with those lights plus some power compacts on my 75 i have about that same amount of light on the floor if not less. its pretty good deal.
#6
Guest_mshi_*
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Posted 06 December 2008 - 06:38 PM
I kind of took some of all the above advice. I replaced the soft whites with 2 daylights (6500K) bulbs. I got creative and rigged the shop lights to sit on the tank like a typical aquarium hood (I have glass tops) and added some foil for better reflection and sealed around the lights to direct/reflect the light into the tank. I only use local livestock and plants so in the spring (Lakes are frozen right now) it is not a problem to get/add more plants. I just need the plants I have now to make it through the winter. This is a Walstad type set up and the plants are the main source of filtration.
#7
Guest_nativeplanter_*
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Posted 08 December 2008 - 02:23 PM
I agree with Mshi; you will get a lot more light from shoplights directed into the tank if you lower them and case them in like a regular hood, and either put tin foil or white paint on the hood inside as a reflector. What I have done to make a hood from shop lights is to take the functional parts out of the light and wire them into a homemade hood. Buying the shoplight and throwing out the metal reflector seems to be cheaper than buying the parts separately. I then mount the ballast on the back side of the hood to help keep the tank cooler (and keep water away from the ballast).
Very nice tank, though!
Very nice tank, though!
#8
Guest_khudgins_*
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Posted 10 December 2008 - 04:17 PM
You're going to be better off with white paint rather than foil as a reflector in general, unless you're VERY careful to lay it out smooth and clean it very regularly. If you want shiny mirror-like reflection, go get a mylar emergency blanket from the camping section of your local big-box store - less than $2.00 and you've got all the reflector you need for a great many tanks.
#9
Guest_nativeplanter_*
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Posted 10 December 2008 - 04:31 PM
I forget where I read it, but somewhere I saw reflective efficiency values for aluminum foil, mylar, and glossy white paint. I was surprised that the aluminum foil beat out the mylar by a margin. If I can find it again, I will post the link here.
#10
Guest_mikez_*
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Posted 10 December 2008 - 04:55 PM
Good advice about directing the light down into the tank. I like the photos showing the floor tiles. Good ilustration of the point!
I have found through a failed experiment that the standard shop lights and bulbs do not have enough penetration for deep tanks. While I had excellent success in 20 and 30 longs, my 90 gallon tank has finally beaten me. I fought the algae for about a year and have now given up. My next project is to tear it down and use the 90 for a stream tank and move what plants are left to a 55. Buying better lights is not an option for my budget.
I have found through a failed experiment that the standard shop lights and bulbs do not have enough penetration for deep tanks. While I had excellent success in 20 and 30 longs, my 90 gallon tank has finally beaten me. I fought the algae for about a year and have now given up. My next project is to tear it down and use the 90 for a stream tank and move what plants are left to a 55. Buying better lights is not an option for my budget.
#11
Guest_nativeplanter_*
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Posted 12 December 2008 - 12:24 PM
Yeah, 90 gallons is really deep.
#12
Guest_Newt_*
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Posted 12 December 2008 - 04:24 PM
Just a thought- does anyone use submerged lights in aquaria? They're readily available, though I don't know how difficult it would be to find lamps with appropriate spectra. It could be a nice way to add extra light in a big planted tank.
#13
Guest_pmk00001_*
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Posted 12 December 2008 - 04:35 PM
Just a thought- does anyone use submerged lights in aquaria? They're readily available, though I don't know how difficult it would be to find lamps with appropriate spectra. It could be a nice way to add extra light in a big planted tank.
I think the heat would probably kill that idea.
LED's might work though? Seems like that might be the next "big" thing in aquaria lighting.
#14
Guest_Clayton_*
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Posted 12 December 2008 - 04:48 PM
I believe most of the submersible tubes are LED lights and output very little heat. Depending on the tank the heat might not be a problem at all. It could make an interesting addition to tank with both tall light loving plants as well as light loving foreground plants. If you could find the appropriate spectrum it might be an interesting experiment to just run all of the lighting on the bottom of the tank. I'm sure you'd get plants doing some interesting things to pick up the light.
#15
Guest_Newt_*
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Posted 12 December 2008 - 04:56 PM
As far as I know most submerged lights are either halogen or LED. Halogen are no-go, but the LEDs should be OK if the spectrum is useable. I was imagining something like recessed lights on the underside of a big piece of driftwood...could be nice.
#16
Guest_scott361_*
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Posted 12 December 2008 - 09:20 PM
I just use six shoplights.
They're a mixture of GE full spectrum sunlight and aquarium lights.
I have to make sure that both the submerged plants and the one above(orchids, mosses, ferns, etc) get a decent spectrum.
They likely need change now, anyway.
I just keep an eye on growth and when I notice a decline...
It's past time and they get replaced.
I've thought about alternatives, but I've never got around to doing anything about it.
Actually, I've thought about alternatives to a lot of things, but...!
They've been just balanced semi-carefully above and covered with a few large sheets of foil.
(Nothing has been fried yet!)
It only takes two large sheets and, if they get torn, I change 'em.
Not exactly show quality, but whatever!;~)
If anyone complains, they better be willing to build me something better! :~)
And I want to see what their tank looks like first!
I just care that everything grows and I don't have small planes trying to land.
If you want to see glare, put on your sunglasses and check out my orchid room!;~)
Scott
They're a mixture of GE full spectrum sunlight and aquarium lights.
I have to make sure that both the submerged plants and the one above(orchids, mosses, ferns, etc) get a decent spectrum.
They likely need change now, anyway.
I just keep an eye on growth and when I notice a decline...
It's past time and they get replaced.
I've thought about alternatives, but I've never got around to doing anything about it.
Actually, I've thought about alternatives to a lot of things, but...!
They've been just balanced semi-carefully above and covered with a few large sheets of foil.
(Nothing has been fried yet!)
It only takes two large sheets and, if they get torn, I change 'em.
Not exactly show quality, but whatever!;~)
If anyone complains, they better be willing to build me something better! :~)
And I want to see what their tank looks like first!
I just care that everything grows and I don't have small planes trying to land.
If you want to see glare, put on your sunglasses and check out my orchid room!;~)
Scott
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