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  Topic Review (Newest First)
04-16-2016 03:29 AM
robchang
Quote:
Originally Posted by jraculya View Post
robchang, did you try those lights?
Actually what I decided on was the phillips 23w CFL that are 6500k. I have one lighting a 3 gallon that is about 10" to substrate and I'm growing glosso that is spreading like a carpet and not growing tall.

Sent from my XT1094 using Tapatalk
04-15-2016 11:46 PM
GrampsGrunge
Quote:
Originally Posted by robchang View Post
Thanks for all the knowledge shared in this thread i4x4 and Hoppy! I am revisiting this thread yet again to determine if there has been any research done about flood lights? I just saw this deal at Home Depot and trying to figure out an economical way to light several small planted tanks.

TCP 65W Equivalent Day light BR30 Non-Dimmable LED Flood Light Bulb (6-Pack)-LBR301050KND6 - The Home Depot

It seems the best bang for the buck proven by this thread is a clamp light + 23w CFL which would be around $9 + $4 = $13 per light

I'm wondering if a CFL or LED floodlight is used + cheap fixture would give similar/better results. For example a 13w CFL = 800 lumens and a 10w LED flood (like the one in the link) is 700 lumens, but has the "built in reflector". So how does clamp light + 13w CFL compare to a 10w LED flood light + cheapo light fixture?
They uprated the Non-dimmable TCP daylight 60 watt equivalent A19's they're now considered to be 850 lumens. Mine are certainly real bright.
04-14-2016 06:48 PM
jraculya robchang, did you try those lights?
01-25-2016 03:50 PM
robchang
Quote:
Originally Posted by Hoppy View Post
Someone needs to do some PAR meter testing of those CFL floodlight bulbs before we can know what PAR they give vs distance. Or, if someone has a burned out bulb, they could carefully disassemble it to see what the reflector is like.
Thanks for all the knowledge shared in this thread i4x4 and Hoppy! I am revisiting this thread yet again to determine if there has been any research done about flood lights? I just saw this deal at Home Depot and trying to figure out an economical way to light several small planted tanks.

TCP 65W Equivalent Day light BR30 Non-Dimmable LED Flood Light Bulb (6-Pack)-LBR301050KND6 - The Home Depot

It seems the best bang for the buck proven by this thread is a clamp light + 23w CFL which would be around $9 + $4 = $13 per light

I'm wondering if a CFL or LED floodlight is used + cheap fixture would give similar/better results. For example a 13w CFL = 800 lumens and a 10w LED flood (like the one in the link) is 700 lumens, but has the "built in reflector". So how does clamp light + 13w CFL compare to a 10w LED flood light + cheapo light fixture?
09-28-2015 02:41 PM
jraculya Until I can find a PAR meter to borrow, I think the LUX meter will have to work. Evidently, my children require food and clothes. =)
I checked out the DFW club, it doesn't look like they are still active, at least that is the impression I get from their site and the fact their email seems to be down. Are there any members on this forum?
09-27-2015 09:43 PM
Hoppy
Quote:
Originally Posted by i4x4nMore View Post
jraculya,If you can track down a PAR meter, it's much better than dividing by 70 and crossing your fingers.

(Sorry Hoppy, no disrespect.) Just my opinion that the "right" answer is always preferable to an approximate answer if one is serious and success is the driving factor.


Cheers,


-Jeremy
I never cross my fingers!

Seriously: I have found it extremely difficult to get a PAR reading that I feel is right on. Today we have LED lights, which use 660nm red LEDs for some of the light, and near UV LEDs for some of the light. But, the Apogee Quantum PAR meter only captures a fraction of those parts of the spectrum, so it is very likely to give too low readings for that type of light. Even for conventional fluorescent lighting it is critical that we keep our hands and arms out of the tank when taking a reading, or the reading will be off due to either the shade from our arms or reflected light from our skin. I was surprised at how easy it was to see that effect. Also, fluorescent bulbs don't produce a constant intensity from the time they are turned on. The PAR readings will get higher for a few minutes, then drop some over the next few minutes, before settling down to a near constant reading. Older bulbs will give a lower reading than newer bulbs.

Just because a PAR meter says we have 27 PAR doesn't mean we have that. It is only accurate to about +/-5%, so 27 means we have from 26.5 to 27.5 PAR, due to the number of digits we get, and from 25 to 29, with the inaccuracy considered, even if there are no other errors. So, it best to round that reading off to 25-30. This begins to make me wonder if my "divide by 70" estimate is about as good as it is going to get.

When you are really serious about light, and want to hold the light intensity to within a narrow band for each plant, then a good PAR meter is the only way you can get it. But, what about the difference in PAR at the base of the plant and the top of the plant? Those who want to know as accurately as possible what light their plants get should still use a good PAR meter, and they should factor in the variation in light over the whole plant. Most of us, who just want a beautiful planted tank, and the confidence that they have a light level that is consistent with the fertilizing, CO2 injection, and plant species they have, can in most cases do that with a cheap lux meter.
09-27-2015 06:54 AM
i4x4nMore jraculya, if you're bent on finding a PAR meter, try the Dallas/Ft. Worth aquatic plant club. The Aquatic Gardners Association also has lot of members in Dallas. Either group might have a PAR meter which could be borrowed. Also worth checking out the groups themselves! - lots of nice, knowledgeable people there.

If you can borrow a PAR meter, or afford one, it really is an invaluable tool; especially if you go off the beaten path and come up with your own DIY lighting setup. Approximating will only get you so far. And it won't show you the immediate effect of changing some aspect of your configuration. It also won't show you the "dead spots" in your tank, or the effect of grow-in, as your plants start to shadow each other.

I guess it depends on how much you care about it.... If you're just a dabbler and want to throw some plants in tank and know that you are in the ballpark with your lighting, then maybe hoppy's approximation will fit the bill - provided you can apply it to your situation.

For me, it would be nice to know, without a doubt, that my chosen lighting was "just right", then I could move on to fertz and water chemistry knowing that one variable was out of the equation. Especially as a beginner...

You don't need to be writing a research paper in order for a PAR meter to be an invaluable tool when setting up a new tank. A $400 PAR meter arguably gives you more ammunition over time than a $400 CO2 setup. (Yet, people have no problem dropping cash on the latter!) If you can track down a PAR meter, it's much better than dividing by 70 and crossing your fingers.

(Sorry Hoppy, no disrespect.) Just my opinion that the "right" answer is always preferable to an approximate answer if one is serious and success is the driving factor.


Cheers,


-Jeremy
09-27-2015 04:31 AM
Hoppy
Quote:
Originally Posted by jraculya View Post
Thank you for the quick response! I wish I had found this post 6 months ago. There is so much conflicting info to wade through, that it is rather daunting for a first timer! I just started my first planted tank and this would have been very helpful during setup.

Now I need to see if I can find a PAR meter in Dallas.

Thanks again!
You can buy a $20 digital lux meter from several different online stores, including Ebay and Amazon. If you prop your aquarium light across a couple of chairs, then measure the light intensity, in lux, with the meter at the same distance your aquarium light will be from the substrate. Divide that number by 70 and you will have a reasonably good estimate of the light intensity in PAR. You get about the same reading when you measure PAR in water as you do in air, for the distances we are concerned with (2 feet or less), so you don't need to correct this number for the effect of the water. If you were planning to write a research paper based on your readings you would want to use a real PAR meter instead of this method, but we hobbyists rarely do research papers.
09-27-2015 03:25 AM
jraculya Thank you for the quick response! I wish I had found this post 6 months ago. There is so much conflicting info to wade through, that it is rather daunting for a first timer! I just started my first planted tank and this would have been very helpful during setup.

Now I need to see if I can find a PAR meter in Dallas.

Thanks again!
09-26-2015 09:47 PM
i4x4nMore If your interest is lighting "intensity", then PAR is what you need to consider. The color temperature of the light source is not a critical factor for general growth in aquariums. It can be shown that typical aquarium plants thrive in a very wide range of color temperature ranging from 2800K to 15000K. Getting the light intensity (PAR) right for your aquarium setup is much more crucial than knowing which wavelengths (CCT Kelvin) are present in the light source... assuming it is a broad spectrum light source.

CFLs and all fluorescent sources, generally have a descent range of wavelengths which will contribute to photosynthesis. However, they are not smooth continuous sources like the sun, incandescent, or metal halide sources etc. As such "color temperature" has a very loose meaning for them. Generally, the manufacture is trying to convey how warm or cool the "color" of the light is when they list the color temperature on the bulb. A lot of people target 6500 kelvin (CCT) in an attempt to mimic "daylight". But, unfortunately, fluorescent technology doesn't even come close to mimicking the daylight frequency spectrum of the sun. Any technology that uses UV light to excite phosphors is going to have this quality... but it just goes to show that plants really don't care as long as there is enough "intensity" to the light source.

If your aim was to study the plant's physiological response to different frequency spectrums, then color temperature would have more importance. But, even then, you'd need to use a spectrum analyzer to look at the frequency content in your source. Color temperature is only truly meaningful for light sources that are "black body radiators"... think, anything that glows from red, to orange, to yellow, to blue, to white as it gets hotter and hotter. Fluorescent tubes and LEDs do not do this!

If one was studying plant growth and trying to achieve some kind of "maxium growth", or flowering, or some other expression of the plant, then the frequency spectrum of the light source could probably come into play. But has a hobbyist, just trying to get good growth, the color temperature is not an important factor.

Cheers,

-Jeremy

Bump: Glad to see those CFL slides are still kicking!

(Probably time to update the PAR ranges for low, medium, and high... )

Cheers,

-Jeremy
09-25-2015 08:39 PM
jraculya Please forgive me for posting on an old thread.

After looking at the slides that 4x4 created, my question is: Is PAR more important than Kelvin or are they equally important?
01-09-2015 04:49 PM
Hoppy
Quote:
Originally Posted by kzeller View Post
What ones did you use?
I used "work lights" from Home Depot, but as far as I can tell, there aren't any significant differences among the thin aluminum dome type reflectors from various stores. Only the diameter and the prices are different.
01-07-2015 08:51 PM
kzeller
Quote:
Originally Posted by Hoppy View Post
... The ones I used were about 8 inches in diameter, as I recall, and they easily covered a 12 inch front to back tank - both a 10 gallon and a 15H.
What ones did you use?
01-02-2015 11:44 PM
Cochepaille
Quote:
Originally Posted by Hoppy View Post
One bulb at about 24 inches should give you about 20 PAR. Most of the tank areas will get light from 4 bulbs, so the maximum PAR should be 80. But, the bulbs are separated enough that you won't get anywhere near full overlap of the circles of light, so my guess is you will get an average of about 40-50 PAR. That is more than enough for low light plants. But, it is also possible that you will get even less PAR, perhaps as low as 30 PAR. And, that would be a good level for low light, non-CO2 plant growing.
Well we were both way, way off! I was expecting about the same result, but here's what I got with the 8" reflectors hung 2" from the water line with 23w (100w equivalent) "daylight" bulbs and the PAR meter placed on the bottom of the tank (no substrate). Also, for those of you who don't want to skip back to read previous entries, my tank is 18" wide, 60" long and 22" from waterline to floor. Note that I only measured PAR data for 1/2 the tank because, well, I would hope that the results on the other side would be a mirror image!

11-07-2014 09:05 PM
burr740
Quote:
Originally Posted by hplowe View Post
This looks JUST like the tank I own, I have a Marineland 60g, it is 48" long x 12" wide by 24" tall, I currently have 4 23w 6500k CFL's in my stock hoods. If I go to 4 of these reflectors like you have pictured, How can I determine what kind of lighting I am getting?
There's some charts on page 2 that might help - http://www.plantedtank.net/forums/sh...t=85667&page=2
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