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Planted Tank Lighting Help

2353 Views 13 Replies 5 Participants Last post by  DKRST
Happy Holidays everyone!

I got a new 75 gallon aquarium for Christmas, very excited to set it up but want to do it right this time! I currently have a 29 gallon planted tank but it was my first planted and it had been a wild learning experience (poor substrate, high lighting with no CO2, plants put in over time rather than set up all at once, it goes on).

I have my substrate plan for my new tank, as well as my hardscape and selected plants to grow. However, I have been confused about lighting for the longest time and even after a lot of readong, still need some help.

This aquarium is 48" long. I need suggestions on a ligthing system to buy, how many watts (I have heard people contradicting the 2 watt per gallon rule), and how high it should be from the top of the tank. I would love to have one that I can build into the canopy that I already have. Among the plants I plan to put in include a carpet of HC at the bottom.

This tank will have CO2 supplementation. The cost of the substrate, my CO2 kit and plants has already made this an expensive project, so a lighting system that doesn't cost an arm and a leg that does the job would be helpful.

I have looked at lights at AH Supply but I don't know the first thing about what I would need.

Thanks for your help!
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Just a quick thought on the lighting. Assuming you don't want to live on the "bleeding edge" of maxing out the CO2 and light levels and you want to use a more relaxed approach....
A couple of T8 bulbs would work well, two separate strip fixtures to spread the light better and you can pull them forward for better viewing when showing off the fish. You can go with T5HO, but it's really too much light and can cause grief if you get anything out of balance slightly. I use the Zoomed T5HO's but only run one bulb on my pressurized CO2 tanks AND elevate the T5HO bulbs over my tanks to about 25" above the substrate!
I''m running a couple of T8's on my 125 (sitting on the cover glass) and the plants in that tank are doing very well without any CO2.
You can probably pick up some T8 strip lights at your local home improvement store, although they may not be aesthetically pleasing! Use the "Daylight" bulbs, not the plant bulbs (too dim and red), or if you want a specialty bulb, I like Zoomed's "TropicSun" T8 bulbs, good PAR output and nice color spectrum.

As TFK guru Byron always emphasized - let light be your limiting factor.
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On my very heavily planted 90g, I use one sunbalster 6400k HOt5 and two 15w hydroponic red/blue LEDs purchased off Ebay for $10. There is no co2, but I am able to achieve deep reds and pinks with crazy (too much) growth at the substrate with stargrass and dwarf swords. The sunblaster has a diy reflector and I paid $30 for the ballast, bulb and ac adapter at a hydroponic store. I think two of those in your canopy would be ok with your co2, provided you plant it heavily, or go diy LEDs. The only drawback with HOt5's is you pretty much have to replace the bulb every six months. The growth cuts down considerably at that time.

I have a 120g with one zoomed floramax t8 and a 10 000k 18w LED accent light. It is low light, but the plants grow slow and steady. I think you can go higher light with your co2 setup. That's just what I find.
limiting light is ... can be beneficial or it could be detrimental, it depends on your plants & interests.

algae requires more light to survive
some plants also require more light

algae for some is the bane of their tank and limiting light becomes desirable.
but not all plants can survive with limited light - so when you get plants, check the plants interests and go with that.

most people seem to like 8-10 hours of lighting
my LFS uses T8, for the 10-12 hours they are open, the more demanding plants always die, and the most demanding ones i've seen them receive died within a few days - there simply was not enough light

myself, i've got 3.5 24" T5HO bulbs (one is ... well it lights, but is otherwise dead and should be replaced)
on a 29 gallon tank
lights are on about 15 hours in a day.

i'm somewhere around 3watts per gallon and near 2x the hours of what others follow
my plants are showing deficiencies, (the leaves are pale instead of a deep green i would like to see - i'm thinking boron or manganese - which looks like it's PH based more than anything, ... if i get the PH back down then the availability should improve and everything is happy again. (aside from potassium deficiency symptoms)

but i'm really pushing things with that much light, so it's bound to show deficiency symptoms in all but the most nutrient rich aquariums.

algae is/was a problem, flagfish are solving that issue, ... otherwise when the algae runs out i'm going to be a little concerned about their diet :(

my tank is more of an extreme, and with deficiencies as they are ...
those deficiencies would dissapear with less light,


if light is your limiting factor it's easy, really easy to maintain a healthy tank for aesthetics.
easy is not a guarantee, you've still gotta be doing the right things, but you've got a huge margine for error and it solves algae issues if that's a concern for you. (or at least helps)

the more light the more you push things to the limits, the more you have to find that right balance to get things working, ... as i describe in my experience, it's not always easy. i have never heard anyone else pushing things to 15 hours of lighting a day, i hear many plants are at 2-3 watts per gallon using that measure.

for what i am thinking for a future tank, i would have the possibility of 7watts per gallon, (and i'd likely keep the 15 hours per day), ... some plants could never handle this much light.

i think about nature, outside, ...

even at 7watts per gallon, 15 hours per day, ... on a sunny day, i think there is more light from the sun, mid summer, more light and (where i live) about the same hours.

there are tons of ways to go, ... get what you find is comfortable.
look at the plants you want first, find what plants you have access to first - work with this list.

with the plants you have access too, find the ones you want most - if your going through your LFS - some may give you a list of what they have access to (more than what they've got in their tanks).

work with that, find the ones you want, see if they are low light (and these can be they survive well in low light, or they could be they cannot survive in intense light)
find the ones you want, see if they have high intense light demands (these will not survive in low light)

get this list, then get your lights

it would really suck to get plants that can't deal with your lighting

as for lighting, ... i recommend
i do not sponsor them, or endorse them or anything like that
lighting there is the cheapest i have found, at times 1/4 the price of the better known brands.

but remember, for 1/4 the price that's the quality your getting.
the lighting i am running is from there, ... the whole 4x T5HO light set i got, would cost me as much as getting 4 T5HO bulbs alone (no fixture)
so they are cheap, you get what you pay for, but they're cheap enough to make it worth while.

you could easily get better light fixtures anywhere else - but not at that price


so ...

figure out your plants first
base your lighting around your plants your after.

then get your lights and your plants

i'd recommend 6500K, or specialty bulbs
a little bit of looking on the 6500K bulbs gives you an idea

they are a mix of what the plants want (lots of blue & red that the plants want) and a huge green spike (so it appeals to us, the buyer)

or you get specialty bulbs that are designed for your plants with little interest on how it appears to us (due to photosynthesis demands, ... i'm sure they're very bright for the plants, but to our eyes these bulbs appear rather dim.)
an example of the more extreme in this area - Hydroponic Lamp 225 LED Grow light Panel Red Blue 110 V
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as i re-red your post

i'd recommend at looking at aquatraders then, ... $100 for a cheap fixture vs. $400 for a high-end one, ... keep your options open

maybe i'm old-fashioned i dono, i like fluorescent and likely always will even when they are discontinued.
the little bits i have seen, when it comes to light intensity, current fluorescent technology, ... 1 watt is 1 watt, fluorescent or LED

you can have light with LED at lower wattage use, but for intensity, your cranking the watts up till your using as much power as a fluorescent :-?

i could be totally wrong on LED vs. fluorescent power consumption vs light output

for lighting spectrum, ... LED is set, the ability for fine tuning the spectrum is difficult, each LED is specific, and they mix LEDs to give a general overall.

for fluorescent they have powder to provide ... well whatever spectrum they want with whatever levels they want... more blue, more deep ultraviolet, more green, red, yellow, even moving into near infrared, ... you name it they can provide a mix for it, and a mix for a combination that can really cater to plant demands for photo synthesis.

replacing LED vs. fluorescent ... replacing LEDs your replacing the entire fixture.
replacing Fluorescent, once you have the fixture, just replace the bulbs (even cheaper)

technology down the road we may see LEDs that really shine and prove to be superior in every way, even competitive costs.

but ... it's going to take a few decades.

computer screens the old glass screen vs LED screens now, ... still the old glass CRTs are better, but you can't find any on the market, unless your going for special interests and they have a price to match, ... if LED was so superior for image quality they'd be using it too

LED has no flicker that the old CRT did (and that's it's fail), but beats LED in every other way.

so i'm expecting the same trend in technology development in fluorescent vs LED, ... there's going to be something that says fluorescent is always got that LED isn't capable of, maybe they'll figure out a system to compensate, maybe not, maybe never, ... but let things take a few decades and it's all going to be LED anyway.

for now, fluorescent is cheaper, comparative to use for power consumption when you really want intensity, and far cheaper to replace when things start dying.

... or at least that's where i stand.
i could be wrong
i could be old-fashioned
i could be stubborn


a google image search on 6500k spectrum
a google image search on photosynthesis spectrum

the 6500K lighting temperature (not actual temperature - it's a color light #)
this color # is known for being a good base to pick for growing plants (and research even finds this to be beneficial for coral tanks - even if overlooked and not used)

you will notice that the photosysnthesis search gives a distinctive "M" type shape of blues and reds being what the plants are known to use.

the 6500K light search you'll start to see charts that show a simular 'm' shape, (you may have to use your imagination for some :-(

this is what is sought for growing plants
a lower "cooler" # the lights have more reds (or less blues - or a combination)
a higher "warmer" # the lights have more blues (or less reds - or a combination)

the 10,000K bulbs recommended for coral tanks leave a very 'blue' light
a 'cool white' could be anywhere from 3000K to 5000K used for room lighting, lots of red, almost no blue, and an over excessive green.

plants reflect green, they don't use it
our eyes are most responsive with green, so we see it very bright (also why typical 6500K growing lights have a nice big green spike)

if you do a google image search, you could change your search from 6500K to 8,000K or 10,000K or even 20,000K (all used in reef tanks) and you'll notice less reds, more blues as things slowly make their shift
if you change your search down to 5000K or 3000K you'll notice the blues disappear and the reds ... well the reds may get stronger they may disappear as well, ... you'll notice the greens & yellows get very strong for sure.

it gives you a good idea of what they are used for, or what they are trying to mimic.

normal sunlight is fairly well balanced, stronger towards blue, but an even gradient that leaves nothing lacking, it's like a line was drawn and everything is even.

to do this for our aquariums we would be using lots of energy to provide a very bright light to all spectrum's, ... good for "everything" in general, but nothing in particular, ... and how much the plants actually use is limited, ... so that's a lot of energy spent on light for plants that isn't being used efficiently

so we buy and sell lights that are geared towards a specific use, that way we can be very efficient, provide lights that have a purpose and when that purpose is used, they excel and make it worth it.
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if you want more reading i would recommend american aquarium products
lets start here
Aquarium Lighting & Light Information | Reef & Planted | PAR PUR

sure they're a site intending to have you buy their stuff.
but ...
as far as that goes, they seem to be more interested in educating you as their primary focus, and some of the things they've got are very impressive to do the job right

reading through their information won't give you a simple answer
if anything it will complicate things more. but you'll understand why lighting isn't simple, there's a lot of technology, a lot of research that goes into it, and from that a lot of different ways that companies are considering at looking for the best to make it easier for you to buy

even that "the best for you to buy" it's all a competative market, a company comes up with something new, surpasses what was done previously, and the race is on for others to compete and even surpass.

in the end the only way to have what is "best" is what is built up on years and decades of research (LED IS NEW, it has not had the time to find the research behind it to compete with Fluorescent yet - but "new" sells, even if it's garbage)

you want to know how much to get for your tank.

from you could easily get more light than you need for cheap,... then you could turn the extra light off and still be spending less than the big name companies

you could listen to others advice
you could listen to others experiences

you could find that peoples experiences on what to get are so varied you tend to pick something, figure out how to make it work, ... and start telling other people "this is what i do, it works for me, you should do it too"

or you could have a bad experience and be telling others "this is never what you should do"

you've got a budget
you've got a list of plants

don't care what else is said, ... get enough enough light to keep your list of plants happy, and work within your budget

how's that for "enough" light :)
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this article mentions 3+ watts per gallon if your adding CO2

i don't think it matters how you go about it, ... if you want to do it "right" it's going to be expensive

nothing is stopping you from finding something you can live with, and think "well i could upgrade that in the future"
just don't live like this upgrade will happen, live goes on, you may not have the money to upgrade when you really need it if you built your tank with the idea of upgrading, ...

but it's an option that gives you flexibility, ... if you want more later on you don't have to do it expensive right away, get it going, save up for doing it better
Holy crap flear, you sure are stuck on florescents, but one point I would like to make it this:

"replacing LED vs. fluorescent ... replacing LEDs your replacing the entire fixture.
replacing Fluorescent, once you have the fixture, just replace the bulbs (even cheaper)"

Yes, you must replace the the whole fixture in LEDs, but say you are running them on an 8 hr photoperiod, and they 'claim' to run for for 50 000hrs without losing spectrum, than these lights should serve the purpose of growing plants for 17ish years without replacing anything. Replacing the t8's every year at min. would cost you say ~20 x 2 t8 for the life of the LEDs (17) at $680.

I'm a bit tiered right now, but I think I did the math about right, I'm just saying that I am experimenting with the LEDs myself and have found them to be impressive. I have only played with cheaper LEDs, and of course, you get what you pay for, and intend to go with Buildmyled when I can afford it, but for now, I am having fun experimenting with LED colour and spectrum of less expensive models, and have found them to work and just wanted to share what I have found so far. Don't worry, I am not offended at all, fluorescent is a sure shot way to go, but I am looking at more environmentally friendly alternatives that do not use mercury just to throw away somewhere when the bulb loses just enough spectrum not to grow the plants as well anymore.
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forgot about length of life of fluorescent vs LED.
yes, with that in mind LED is far cheaper in the long run

i'm still waiting till i understand more of the spectrum of LED and PAR vs PUR. when the technology catches up so LED is equal or superior to Fluorescent.

like i said about the computer monitor LED vs CRT, ... LED beats CRT in one way, no flicker. yet for all CRT has over LED, you still can't find CRT on the market

i don't want that to be the same scenario for aquarium lighting
If you can afford the LED's they are certainly energy-efficient, although I wouldn't (yet) consider them cost efficient!
Forget the Watts/gallon, it's virtually useless with the various metal halide, T5, T8, CFL and LEDs - it was calculated using the old T12 bulbs and the light's reflector makes a big difference also.
Keep the light at/under 8 hours/day initially, sneak it up over time if you want to experiment and watch out for BBA over time.

My comment about light being the limiting factor is that you want to avoid algae, nutrient deficiencies, CO2 deficiencies, and the easiest way to do that is to not take your light too terribly high. Remember that light duration is NOT a complete solution for intensity of lighting if it's just too strong.
You don't necessarily need insanely high light to grow beautiful plants. My plant guru friend grows all kinds of rare and beautiful plants with medium lighting, he is, however, very very particular with his fertilization, substrate composition and CO2 levels.

T5HOs are usually a good start for a high tech tank as LED lights do cost an arm and a leg :) I use LEDs myself and only find it affordable because I run very small tanks. Otherwise I use fluorescents...but they last me a year at most before i need to change them out again :(

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Keep the light at/under 8 hours/day initially, sneak it up over time if you want to experiment and watch out for BBA over time.
Just to say on that note, what do you know about BBA over time with too much light? I mean I want to know what you know cuz I get this with my 1 x HOt5 in a 20" deep tank up for a year, no c02. Is this where I went wrong? This could be a good 'warn' by experience.
BBA tends to be a problem in tanks with soft water and fluctuating CO2. Not introducing any BBA into your tank and dipping new plants for algae is a good habit to get into :)

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Agree with the plant dip for a variety of reasons (snail and parasites), but you'll find BBA spores in the air, so you can't totally keep it out that way. BBA is caused by fluctuating CO2, varying nutrients and/or too much light. Most of the time, it's too much light that is the culprit (in non-co2-enriched tanks, anyway). It's a pain to get rid of but my first recommendation to battle BBA is to reduce the light intensity and photoperiod (below 8 hours/day, might go as low as 6/day temporarily). there are LOTs of anti-BBA threads here, but prune as much out as you can, clean any hardscape to remove BBA that's taken up residence, and you can try "Excel" to inhibit the algae growth a bit (caution, a few plants don't like Excel at all).

I don't want to further hijack this thread, so if you want more on exactly what I've done, shoot me a PM, but what I said above is basically it.

Main issue I see is a T5HO light on a 20" deep tank = too much light intensity! Try using fiberglass window screening over the tank to cut the light by 40%
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