How decent is the Fluval LED light that comes with the 200L tank?

[oreo57]

Thanks oreo, so that would equate to about 8 lumens per litre, well below the 10-20 level that's often quoted for low level plants.

Edit:

Having slept on it @oreo57 it begs the questions that lumens in and of themselves are meaningless in relation to plant growth, which isn't really ground breaking news.

Or these modern led's put out far more par values than the wattage would once of a day suggest there capable of.

The light compensation point of aquatic plants is far below what was previously assumed.

Or I've somehow got lucky and managed to defy the laws of physics with my lights.

Watts can be a rough indicator of lumens based on most LEDs (and actually most other light sources i.e tubes metal halide)
They have an efficiency of about 70-100L/watt.
Old style 3 watt-ers were around 40-60 though.

Yes lumens are err "antiquated" in this day and age. Does help to at least compare led lights.
Mostly because the "delivery" is equal.
120 degree beam angle for 80% of the lights out there.
No worries of reflector differences and not much for shields except if "frosted".

Next measurement up would be LUX which is lumens/area.
Using simple math and some stats one can determine LUX

Lumens to lux (lx) conversion calculator

Lumens (lm) to lux (lx) conversion calculator and how to calculate.

www.rapidtables.com

Then LUX to PAR.

Convert Lux to PPFD - Online Calculator | Waveform Lighting

Online calculator to convert illuminance (lux) to PPFD (micromoles per second per meter squared).

www.waveformlighting.com

But complicated and prone to errors though it can get close.
"PAR" or more correctly PPFD is the defacto standard.

So since LEDs are very directional and usually hung low on the tank you can "beat" physics by not wasting photons.
At one time standard thinking was 1/2W LED = 1W t5
Efficiency was similar, delivery was not.

LED's currently are in the 120-150L/watt 20-50% more efficient than tubes.
That's diode efficiency not system but if using "state of the art" diodes and the delivery efficieny you can "beat"
T5's ect. easily in less watts/PAR

Last thing is lumens are weighed around the green spectrum so blue "lumens" are recorded as less than green
lumens though they (assumption) both generate the same amout of photons (PAR).

 

[John q]

Thanks again for a very thorough explanation oreo, still trying to get my head round those calculators but I'm fairly persistent so will get there eventually.

I think I mentioned at some point in the thread that I added an aquasky 2 to my set up, that light is 33w and rated at 2260 lm, yet the 14.5w standard aquasky delivers 1950 lm. Surely they wouldn't have used less efficient led's in the newer light... or would they?

So since LEDs are very directional and usually hung low on the tank you can "beat" physics by not wasting photons.

I think that is possibly the answer here, the roma range positions its light about 30mm above the water line and they're hooded so no valuable light escapes, maybe this explains why a seemingly weak light can work in its intended surroundings.

 

[Muso1981]

Thanks for the replies, I must admit most of what you're saying is over my head though.

The Aquadip has ran out and I threw the bottle away so have no idea what it contains. I have bought become Tropica Premium Nutrition.

I know it's hard to recommend what to do but on one hand I've got a bit of algae which I understand means too much light?? Funny thing is how I had no problem with the old t5s in the juwel tank but now the plants are in the new tank they're not doing so well.

Edit: just re-read the thread again and it sounds like my current light isn't strong enough. Thanks for all the info, looks like I will be getting the fluval plant 3.0 light then.

 

[Muso1981]

I've just done some basic calculations using lumens.

The 120 Litre tank with the T5 tubes equated to 29 lumens per litre

The new 200 litre tank with stock LED equates to 9.75 lumens per litre.

So it sounds pretty darn obvious now that the stock LED isn't going to work for plants. I feel a bit miffed as the guy in the fish shop told me that the LED would be a good upgrade for growing plants.

Thanks everyone for your help with this situation, now I just need to get a new light to save my plants.

 

[Muso1981]

Can anyone confirm if the fluval plant 3.0 is the light to get? It's 46 watts so not massively powerful and pretty expensive at around £200. But it will fit the tank perfectly.

 

[John q]

I can confirm that you'll get seriously good algae growth and melting plants with an extra 46w in your low tech tank.

On a serious note and as I've said previously I think the issues you're having aren't related to lack of light. If however you decide to get another light then the plant 3 will fit the tank well and running it alongside the basic aquasky will give you a far better spread of light.

Just make sure you run the light at a very low percentage and when you do increase the intensity, do it slowly.

 

[Muso1981]

Hi @John q I'm totally confused now, the calculated lumens per litre I mentioned above. The previous tank was way higher that what I have now.

My previous tank had horrible blue gravel as I didn't know better. The new tank has Tropica Soil powder which is for plants.

I don't see the point in buying a more powerful light only to run it at low power?
Should I just get another of the same light?

What do you suggest, maybe leave it a bit as the plants have been in a week and also I have the tropica fertilizer?

Cheers

 

[John q]

Look I'm no expert, let's make that clear.

If it was my tank I'd lower the light intensity a little bit, make sure the flow in the tank is good, and get some additional potassium to add in with your tropica premium. Adding the extra potassium, and ensuring good flow will rule out that being the reason for the holes in your leaves.

Give it a couple of weeks and see if there's any improvement, if not then go out and get a new light. I'd probably get the aquasky 2 which is cheaper and combined with the standard light should be ample light for low tech, but again that's only my opinion.

Edit: I should add the tropica premium contains no nitrogen or phosphate, so unless you've got a decent fish load you might want to get a fertiliser that has that.

 

[Muso1981]

Cheers John, valuable advice and much appreciated. I will go with that and give it a couple of weeks.

Thanks

 

[sparkyweasel]

I agree with John, you need a complete fertiliser. I think the Aquadip is missing Nitrogen and Phosphorus too, but the makers don't seem to want to tell us. 🙂
Assuming the algae you mentioned is green, I think it's unlikely you have too little light. I would certainly try other options before buying an expensive light that could make things worse. 🙂
As Oreo says, lumens are not straightforward, but we struggle on using them, because they are often the only measurement available.

 

[ceg4048]

I've just done some basic calculations using lumens.

The 120 Litre tank with the T5 tubes equated to 29 lumens per litre

The new 200 litre tank with stock LED equates to 9.75 lumens per litre.

So it sounds pretty darn obvious now that the stock LED isn't going to work for plants. I feel a bit miffed as the guy in the fish shop told me that the LED would be a good upgrade for growing plants.

Thanks everyone for your help with this situation, now I just need to get a new light to save my plants.

These numbers are completely irrelevant. Lumens are a measurement of how human beings perceive the world because the human visual cortex is relatively insensitive to blue and red. This measurement has absolutely nothing to do with how plants perceive the world because plants and algae specialize in their ability to perceive to blue and red as well as all the other wavelengths in the visible spectrum. So not only is Lumens a poor judge of the power of a light bulb, but "Lumens per Liter" is an even worse metric for determining the power of a lamp because Liter is a volumetric measurement and the behavior of light is a function of a linear distance, i.e., the light falloff follows the inverse square rule, and a volume tells you nothing of the distance from the bulb to the leaf.

Even Oreo's Lux to PAR conversion does not give exact results because the conversion depends on the distribution of wavelength content of the bulb.

This is why LED lamps are more powerful than most people ever imagine and of course this is why we get into more trouble than we bargained for. If you think getting a new light will save your plants you will be sorely disappointed.

Plants grow by their use of CO2, NOT only by their use of light. Focus more on CO2, if this is a CO2 tank and if it isn't a CO2 tank then focus more on severely reducing the light intensity until your plants can adapt to their environment.

Cheers,

 

[Muso1981]

Thanks @ceg4048 this is all very interesting stuff and I feel like I now need a degree in science to grow plants.

I really don't want to be getting into injecting CO2 as it's too much of a faff. It feels now like everyone is saying my light is powerful enough and it's some other kind of issue. I've got a fairly heavy stock of fish in there and have the new tropica fertilizer so will see how it works for a week.

The reason I've been going down the lighting rabbit hold as old tank had no problems, new tank does. The main difference is the light so did that maths based on the tropica recommendation (they rate their plants difficulty as lumens per litre). And well here I am.

 

[sparkyweasel]

(they rate their plants difficulty as lumens per litre).

I wish they wouldn't.
We know lumens are not very useful.
We know the the volume of the tank doesn't determine how much light it needs. Different shapes of tank with the same volume will not need the same lighting.
The amount of light does not relate to how difficult to grow a plant is. If plant A needs more light than plant B, it isn't harder to grow, it's easy enough to buy a more powerful light if it's actually necessary.

 

[Muso1981]

Hi @sparkyweasel I was just wondering who you are referring to as "we"?

Can anyone point me to an up to date article which explains all of this please? I'd love to understand this more.

 

[John q]

I think Clive's explanation was a fairly straightforward one, well at least in my eyes.

I found this blog @Muso1981 that maybe explains it in more layman's terms.

"LED lights require new thinking about the way we measure light spectrum for use by plants. The typical rating most growers are familiar with is the “lumen”. The definition of the lumen is the total light produced within the range of the human visual response. It tells us nothing about the distribution of that light energy over the spectrum, and most importantly, it doesn’t tell us how much is useful for plants.

The problem with lumens is especially pronounced when measuring light at the far ends of the human visual response curve. Consider three lamps—red, green and blue—each emitting the same number of watts of optical energy. The red and blue lamps would have much lower lumen ratings compared to the green lamp, simply because the human visual response is very low at red and blue, and the highest at green.

That’s why a high lumen rating does not necessarily make a lamp better suited to growing plants.
Similarly, light meters that measure in “lux” tell us very little about a lamp’s plant-growing power. The light sensors in lux meters have their own spectral response curves which may over- or under-measure light at various colors. This is why lux meters usually have different settings for “sunlight,” “fluorescent” and “incandescent” lamps. Again, because lux meters are meant for measuring the amount of light usable by humans, they don’t tell us anything about how plants will respond."

Demystifying Lumens, Lux and PAR (2019) • LumiGrow Learning Center

LED lights require new thinking about the way we measure light spectrum for use by plants. Expand your understanding with this fundamental information.

www.lumigrow.com

 

[Muso1981]

Thanks @John q that's a really good link which explains a lot. It still doesn't help determine how much LED light you need though and pretty much every site I look at mentions watt per litre or lumens per litre. I'm guessing this is because PAR is difficult to accurately measure. So it seems a lot of this light work is down to trial and error due to the variables, but it's possible to work with some basic logic and to start with less rather than too much.

Cheers

 

[John q]

It still doesn't help determine how much LED light you need

No it doesn't.

What specific par readings might work for my tank, might not necessarily work for yours.
In that respect i think for the average Joe like you or me, especially in low tech tanks, Par readings, lumens, lux or wattage are probably irrelevant!

Its all about trial and error, and to be fair that pretty much sums up planted tanks in general, not just lights.

 

[oreo57]

Thanks @John q that's a really good link which explains a lot. It still doesn't help determine how much LED light you need though and pretty much every site I look at mentions watt per litre or lumens per litre. I'm guessing this is because PAR is difficult to accurately measure. So it seems a lot of this light work is down to trial and error due to the variables, but it's possible to work with some basic logic and to start with less rather than too much.

Cheers

Par isn't difficult to measure just err expensive
For a manuf to measure lumens isn't cheap either.

As to leds, since easily dimmed for the most part I'd lean to getting more light than less. 🙂

As to the article...few planted tank-ers need to maximize yield at the likely expense of visual enjoyment.

My usual rant about definitions and the poor use if the "word" PAR .

About PAR, PPF, And PPFD
UNDERSTANDING THE NUMBERS
If you have been researching LED horticulture lighting systems for your plant growth facility, you have likely been bombarded with a variety of metrics that lighting manufacturers use to market their products. Some terms and acronyms you are likely to see include: watts, lumens, LUX, foot candles, PAR, PPF, PPFD, and photon efficiency. While all of these terms do relate to lighting, only a select few really tell you the important metrics of a horticulture lighting system. The purpose of this article is to define these terms and acronyms, correct some common misunderstandings, and help growers understand which metrics are applicable to horticulture lighting systems, and which ones are not.

HUMANS USE LUMENS
Plants and people perceive light very differently from one another. Humans and many other animals use something called photopic vision in well-lit conditions to perceive color and light. Lumens are a unit of measurement based on a model of human eye sensitivity in well-lit conditions, which is why the model is called the photopic response curve (Figure 1). As you can see, the photopic response curve is bell shaped and shows how humans are much more sensitive to green light, than blue or red light. LUX, and foot candle meters measure the intensity of light (using lumens) for commercial and residential lighting applications, with the only difference between the two being the unit of area they are measured over (LUX uses lumen/m2 and foot candle uses lumen/ft2).


Figure 1
Using LUX or foot candle meters to measure the light intensity of horticulture lighting systems will give you varying measurements depending on the spectrum of the light source, even if you are measuring the same intensity of PAR.

The fundamental problem with using LUX or foot candle meters when measuring the light intensity of horticulture lighting systems is the underrepresentation of blue (400 – 500 nm) and red (600 – 700 nm) light in the visible spectrum. Humans may not be efficient at perceiving light in these regions, but plants are highly efficient at using red and blue light to drive photosynthesis. This is why lumens, LUX, and foot candles should never be used as metrics for horticulture lighting.

WHAT IS PAR
PAR is photosynthetic active radiation. PAR light is the wavelengths of light within the visible range of 400 to 700 nanometers (nm) which drive photosynthesis (Figure 1). PAR is a much used (and often misused) term related to horticulture lighting. PAR is NOT a measurement or “metric” like feet, inches or kilos. Rather, it defines the type of light needed to support photosynthesis. The amount and spectral light quality of PAR light are the important metrics to focus on. (To find out more about spectral light quality click here). Quantum sensors are the primary instrument used to quantify the light intensity of horticulture lighting systems. These sensors work by using an optical filter to create a uniform sensitivity to PAR light (Figure 1), and can be used in combination with a light meter to measure instantaneous light intensity or a data logger to measure cumulative light intensity. We
Three important questions you should look to be answered when researching horticulture lighting systems are:
How much PAR the fixture produces (measured as Photosynthetic Photon Flux)?
How much instantaneous PAR from the fixture is available to plants (measured as Photosynthetic Photon Flux Density)?
How much energy is used by the fixture to make PAR available to your plants (measured as Photon Efficiency).
The three key metrics used to answer these questions are:
PAR
PPFD
Photon Efficacy
PPF is photosynthetic photon flux. PPF measures the total amount of PAR that is produced by a lighting system each second. This measurement is taken using a specialized instrument called an integrating sphere that captures and measures essentially all photons emitted by a lighting system. The unit used to express PPF is micromoles per second (μmol/s). This is probably the second most important way of measuring a horticulture lighting system, but, for whatever reason, most lighting companies don’t list this metric. It is important to note that PPF does not tell you how much of the measured light actually lands on the plants, but is an important metric if you want to calculate how efficient a lighting system is at creating PAR.

About PAR, PPF, And PPFD

If you're shopping for horticulture grow lights, you may have seen the terms watts, lumens, LUX, foot candles, PAR, PPF, PPFD, and photon efficiency.

fluence.science

PPFD which is what most are referring to as "PAR" is photosynthetically usable photons (by ONE definition ALL photons between 400-700nm) per second in a defined AREA, micromoles per square meter per second (μmol/m2/s).

Btw many LUX meters use a green filter to emulate the lumen curve. Removing that filter will get one a "better" meter, depending on the photodiode used.
Unfortunately many photodiodes are sort of natural lumen sensors. See S1787-04

 

[sparkyweasel]

Hi @sparkyweasel I was just wondering who you are referring to as "we"?

I think that includes you now. 🙂
John and Oreo's links are very useful if you want to get into the technicalities.
If you do decide to invest in new lights, I think the most useful improvement over incandescent and fluorescent light is that so many LED lights are dimmable, so trial and error is easier and cheaper to do.
I think if you give your plants a couple of weeks with your new fertiliser regime and existing lights you will see an improvement.

 

[oreo57]

Hi,

So I've had my new tank setup and plants/fish all moved over for a week now.
Some plants arn't doing too well (the leaves are getting holes in them) and there is some algae forming on the glass.
Water levels are good and I have the light on for 8 hours a day.
Do you guys think the plants arn't doing well due to lack of light?
I don't plan to use CO2 so have read I shouldn't have too much of a powerful light.
Also how does lighting work in terms of power and time? I.e. would a less powerful light being on longer be equivalent to a more powerful light being on a shorter time?

Maybe time to get back to your initial issue..
First I want to add that I'm terrible at following my own advice but do rely on others and the err scientific method so here goes.
1) Dealing with a new tank and initial growth (generally not depending on no matter how many small plants you start with) it's easy to over light it esp. w/out CO2 and well established plants.
Doesn't mean you have too much light only too much initially.
2) Now on to the Fluval. Initially in the upper portions of the wide tank you have dull zones. Combination of a narrow light, 120 degree beam angle, and closeness to the surface of the water line.
Best idea for your tank and demand would be to raise the light (risers can be bought or made or one could suspend it w/ the extra hanging kit).
The whole point and really w/ any light IF one wants max coverage top/bottom, front back, and some side/side (better to get that w/ a light that fits exactly but not as necessary w/ leds than say t5's)
You should have plenty of "PAR" for now (dimmed) and in the future when the tank fills out more.
As the width decreases so does PAR btw but not extreme, AND this is just the center.
If this is the PAR of 59W led imagine the PAR of lesser wattage types.
Keep in mind that the Fluval has plenty of light that reports low in a lumen measurement but isn't a lot different from a "normal"
led fixture inc RGBW , just whites, and even RGB though suspect that is a bit lower as to recording lumens.
Anyways the point is w/ quality diodes the l/w or PAR/watt will all correlate well between like fixtures.


71PAR @ 18" 59 Watts, 4250 Lumens 1.2Par/watt .017Par/lumen @ 18" 48" light




Finnex 24/7CC 48" 46W, 18" 60 PAR, 1.3PAR/watt ??PAR/Lumen It would surprise me if it wasn't in the range of 4000 lumens @18" 48" light
Beamswork 48" 18" 48 PAR 5200 lumens 60W 0.8Par/watt .009PAR/lumen @ 18" 48" light

Difference of 50,60,70 PAR per fixture is somewhat irrelevant.
Difference in the Fluval lumens from the other 2 is probably mostly due to "pink" and warm white (good deal of red/blue) diodes.
Beamswork watts was est using 120 x .5W emitters. Probably inaccurate on the high side.

Of course this all assumes relative watt efficiency of like diodes and this is a rough estimate.
Point is if you can tolerate a little slop in this watts, lumens, reported par are fairly good indicators of strength.
This does not apply to COB based, larger emitters (1-3W) smaller emitters (well haven't really crunched them ie .1-.2W) or diodes driven on constant current drivers.
Nor does it include more than the "hot spot" so spread and optics (120 vs 90 ect) are not included either. Like I said like fixtures, mid power average diodes , 120 degree lenses, constant voltage, optimized design (low resistor losses)
Feel free to debate this, it's really only a hypothesis not an absolute.

Anyone care to add 18" par measurements 48" light vs wattage of their fixtures "we" could confirm or refute this.
Dead center max readings.
I'm not including lumens only because the only easy measuring device is the
Seneye and I believe it is flawed.
The PAR readings are acceptable, the lumens is way off AFAICT.

Nothing beats real life measurements though.

Again I guess I've drifted off point but again having more power (dimmable) will allow you to adj a bit as your tank grows in.
I'm not encouraging you to spend money as of now.
Nor deviating from the need for "balance" in Ferts/CO2/light.

One more..

2xChihiros Serie A 120cm . 65W . 8000ºK
now with water . 120x50x50 tank . 6,5cm fixture high + 2cm water level = 8,5 cm LED to water
cm PAR PAR (with apogee converter factors**)
10 265 213
20 192 140
30 152 106
40 132 110
48 122 82

Say 48 is close to 45 (18")
130W 122 PAR
.94PAR/watt

so we now have 1.2, 1.3, 0.94, 0.8 PAR/watt
Easily round it to 1PAR/Watt for all of them for a "ballpark" estimate

AT 40 w that would be 48, 52, 37.6, 32
Sample of a classification system.
Except for the 32 most would end up in what the below considers "medium light" 37.6 ..close enough


Plenty of lights here to play w/ numbers.
Assume the difference between 40-50cm and wattage.


Twinstars are a bit of an outlier
49 @ 33W 1.48PAR/watt 600ES
ZetlightQmaven 96W 1.14PAR/watt
Zetlight Lancia (out of water) 1.18PAR/watt

Product Review - ADA | WASMAS | ZETLIGHT | TWINSTAR | CHIHIROS | LED PAR DATA [The power of light]

This is my older son tank with Chihiros on top: For reference, i took this image side by side with my big tank (7 x 6000ºK + 3 x 4000ºK LED) As you can easely see it's much more cold! (Sorry about phone pictures), Cheers Really like your son's tank, does he have a journal for the scape?

www.ukaps.org

Keep in mind that the measurements should be from the light face to the sensor top of 45cm and preferably 120cm lights or a bit shorter.
Since you are measuring the diode overlap as well as the diodes directly above the sensor.

Seems watts is a slightly better estimate than lumens of possible PAR. 😉
Of course it all changes if diode efficiency increases any more.
Anyways enough (too much) for now.

LAST THING ..AS TO NUMBERS.
Finnex vs Fluval
Watt ratio .78
Par ratio .84
Under 10% difference.

Fluval Plant 3.0 vs. Finnex Planted+ 24/7 CC

Fluval Plant 3.0 vs. Finnex Planted+ 24/7: what light should you spend your money on? Well, you’re here because you want to grow plants in your fish tank, because otherwise you’d probably be looking at cheaper

coolfish.network