Updating the WPG rule (theory)

[Wizzard~Of~Ozz]

Best I can find for T5 is an output of 105L / W initial. High Output drops to 95L / W.. While the number looks good, a 4' bulb is 28w making it's lumens output / bulb = T8.. so 1 T5 bulb = 1 T8 bulb. They seem to want to boast about high lumen output, yet I can find no evidence of this anywhere (trying to sell their product).. I would only recommend T5 over T8 if you are short on realestate over your tank, even then I would recommend using ODNO T8 over T5. IMO T5 offers nothing but a minor savings on your power bill (4w/light * 3 bulbs lets say = 12w over 1000 hours = 1$ and the costs of the bulbs are much higher then the savings.)

ODNO T8 fixtures are the best bang for the $$, and as I see it, it will be for quite some time.

I will add what I can to mention ODNO lighting, but there are more then enough howto's on the net (search for ODNO)

 

[czcz]

GM,

I think if T5-HO was added to the list of light output/watt and possible ODNO outfits that diffent light source selections might be made around here.. Razz

T5 and T5HO calcs (at 104 lumens/watt and 92.6 lumens/watt, respectively) are on the previous page. Both are on the .xls spreadsheet at the top of this page for quick calcs of summed lumens/watt accross many types of bulbs. Assuming ODNO ratios for overdriving and light output hold up for lumens, one could just make the conversion themselves and put it back into all discussed formulas and spreadhseet, while adding supplemental lights of different types

Example attached with 20long, 30w T8 4x ODNO, with 15w T12 to show how the fields fill out. (I used OpenOffice to make the spreadsheet, but as .xls it should work fine in Excel and such.)

Ozz -- current survey numbers. Holding up well. More samples, especially between 15 and 20 lumens/sq in, would help.

          Eq T12 wpg  Lumens   Lumens/sq in   Lighting level
czcz_8_old     4.38   2064.4   13.23          med-high
czcz_8_now     6.88   3242.4   20.78          very high
czcz_20        1.5    1767      4.91          low
rich311K       4.87  10322     28.67          high-very high
Purrbox       14.02   2064.4   28.67          high-very high
Blazer_6       2.35    832      3.48          low
Blazer_10      3.5    2064.4   10.32          med+
gfink_10       3      1767      8.84          med
gfink_29       1.24   2120.4    5.89          low
Jchillin       1.98   8734      8.66          low
fish_old       1.5     883.5    4.42          very low
fish_now       4      2356     11.78          med
CGGorman       3.7   15244.8   14.44          med-high
Ozz            3.7   16372.8   18.95          high
LoneWolf       9.35  41288     47.79          high-very high
ringfinger_29  4.46   7622.4   21.17          high-very high
ringfinger_20  2.19   2580.5    7.17          low
ringfinger_10  1.5     883.5    4.42          low

What do you think of surveying off-site with PHP with MySQL? Might be better if response on AA stays small.

 

[Wizzard~Of~Ozz]

I'll see what I can whip up for an entry form. Getting it to store and produce numbers is no problem. To establish the types of lights to be entered it would be.

T12
T10
T8
T6
T5
T5HO
CF
Screwin CF

is VHO T12 equiv. in lumens/watt?

Also I figured out how to find the spectrum of a bulb.. well science class was fun and we didn't play with prizm's much, they have their purpose. Don't have one? look from the front bottom of your tank up towards your lights

 

[Lonewolfblue]

So where are we now on the w/g? With 520W CF on a 75G, what are we looking at for w/g?

 

[czcz]

Ozz,

In Busko's article he has one 4100K VHO sample that is 313lumens/watt. Quick google search only gave this as useable, again with 4100K having much more lumens/watt than 6500K, but here's data with the two 6500K bulbs until someone gets more samples:

bulb             watt  lumens  lumens/watt    
F72T12/D/VHO/TSC  72    6400    88.9
F96T12/D/VHO/TSC  96    8750    91.1

avg 90.2 lumens/watt

1.5w T12VHO = 1w T12

LoneWolfBlue,
As Ozz said earlier 520w CF over 75g is insanity You are between 9.0 and 9.4 wpg using the above calcs for equiv T12 wpg, with the difference being a sig fig thing. Since you already have the fixtures, consider running actinic maybe. Notce how halving your light (to the original 260w CF) is in line or past the light level of established high light tanks.

 

[Lonewolfblue]

Well, with just the 260W, the plants were not pearling at all. They only started pearling after adding the extra lighting. I was thinking of taking 1 set of the bulbs out of the 2nd fixture and putting in 50/50 bulbs, still thinking on that one.

 

[travis simonson]

Not sure if you've read this article regarding lighting on Aquabotanic but it is very informative. It regards PAR (photosynthetically active radiation) as more important than raw lumens and gives a very nice table of figures that may help refine your spreadsheet a bit. I don't claim to understand it in-depth, but I think I need some metal halides now

 

[travis simonson]

Here's another fascinating article on rethinking the watts per gallon rule based on Takashi Amano's use of lighting in different sized aquaria. Illustrates very well the non-linear nature of lighting wattage as tank volume increases.

 

[h8z2luze]

You guys are killin me with all the math! Can someone tell me what wpg I have if I have 2 of these....

http://www.aquariumadvice.com/reviewpost/showproduct.php?product=206

Thanks, I wish I could figure it out myself but you people seem much smarter

 

[Wizzard~Of~Ozz]

There is a calculator on the page I wrote Here I'm not sure how it would apply to saltwater tho.

Travis, that is why I said HID lights are in a class of their own. Unfortunately PAR is not a number that can be found by simply looking at the packages, but both articles are very well written.

I'm still considering Dual 250W MH over a 125Gal.. Just to see how good HID Bulbs are. It also helps that I can get 250w fixtures for free, tho I'ld probably need some new bulbs.

 

[travis simonson]

h8z2luze: So you've got two 2x28w T5 fixtures for a total of 4x28w T5 lighting with 2x28w being 10000K and 2x28w being Actinic 03?

I've always figured T5s as the same as CF for lighting purposes. They are the same bulbs essentially, with CFs being bent back on themselves and slightly less efficient due to strikeback.

That said, you can basically discount the 56w of Actinic 03 lighting you've got for plant growing purposes. I would say it only contributes about 25% or less of its wattage toward PAR (photosynthetically active radiation) so you might add a small fraction of its wattage toward your total. I do like the way it makes colors stand out though, and some theories suggest that its heavy blue spectrum light is effective in causing shorter internodal (read: bushier) growth in plants. Effectively you've got a little over 60 watts of CF plant-usable lighting.

What size tank do you have? Is it the 50G in your profile?

 

[AshleyXavier]

It has more to do with the intensity. There is also more to the WPG rule then it takes into account. so 6WPG according to the calc is not always a bad thing. the depth of the tank has some play too. someone posted the calculation that takes into account the distance from the substrate.. and I noticed when I used that calc. my recommended WPG was somewhere much higher then 4WPG to get the equivilent of "high light".

The purpose of this was more to address the problem some are having by trying to hit 4WPG of CF lighting and not taking into the account that CF bulbs are 175% more lumenous then the bulb the "WPG Rule" was based on.. however, with that, the WPG was also wrong to start with since it doesn't take into account the height from the substrate, the spectrum of the bulb etc.. most people that are hitting 4WPG are doing it on 20Gal or less tanks, they tend to be very short (sub 18") and that is where the problem comes in.

As for bringing out the reds. I can tell you it is not always lighting related. with the exact same light over a tank (same intensity), I have had rosenervig that was very red, and now it's very green.. 2 things that changed. I removed the actinic 50/50 bulb. I also allowed the nitrates to run up a bit higher.. So either the absence of actinic light or the high trates cause the plant to lose it's red..

I'll try to write up a better article with more variables taken into account. I've learned a lot about lighting.. figure it's time to apply some of it. Also, Philips is sending me some spectral outputs for some of their "home depot" brand lights. (Daylight Deluxe and Natural sunshine). it should be interesting to see what else is in the documentation and how they compare to the bulbs that are 10x the price at the LFS..

I believe I read in some articles that the plants need actintic light to stay red. Can't remember why exactly but my guess will be that since plants usually makes use of the red & blue spectrum for photosynthesis as the green leaves reflect off green light. Red leaves will actually reflect off red light? leaving it only to absorb blue light, if there is insufficient blue light for the plant to absorb, the plant starts to lose it's redness and turn green.

The part about red plants needing blue light is correct, the rest are my speculations... If you want to test, just plug in an actintic light to your tank.

 

[Jchillin]

Yes, blue is essential...but not of the actinic variety I believe. Blue penetrates further into the water than all the others.

 

[h8z2luze]

Yes it is the 50 in my pro. I am kind of confused. So how many watts do I have compared to other lights? lol. Sorry.

 

[Wizzard~Of~Ozz]

This won't apply correctly to Saltwater, well the light level won't but the output of a single T5 28w bulb is equal to 51w NO lighting. so your 4 bulbs have an equivelent light of 200w of T12 lighting. actinic work for reefs and such, but not for plants so much (they have an impact, just not the same kind)

 

[ringfinger]

Does anyone have any kids with a science fair project coming up? This would be a fun idea to play with, more so than deciding whether a plant grows better in a window or in a closet.

 

[h8z2luze]

Cool so I really have like 112 watts of sunlight and 112 watts of actinic.

 

[greenmaji]

Not sure if you've read this article regarding lighting on Aquabotanic but it is very informative. It regards PAR (photosynthetically active radiation) as more important than raw lumens and gives a very nice table of figures that may help refine your spreadsheet a bit. I don't claim to understand it in-depth, but I think I need some metal halides now

Heh.. I would think after reading those charts you would be excited about ODNO'ing some Philips Advantage fluorescent, 5000K F32T8 bulbs..

I would think some (you pick)Watt Iwasaki 6500K MH with PFO electronic ballasts might just do the trick for nearly any high light needs situation.

 

[jcarlilesiu]

can we possibly bump this into the stickies, or at least incorporate it into the information already provided in the light sticky... im spending alot of time searching this out on several occasions.

Everytime I think "man.. do i really have 6 wpg" i come back here for the information to verify.

 

[czcz]

Added links to the lighting sticky as a reply. BTW, here's your data for the current fixture from your thread. The last one is with one 50/50 bulb (with no useful output from actinic), in case you're curious about levels.

jcarlilesiu's 56g
          Eq T12 wpg  Lumens   Lumens/sq in
192w CF         4.62  15244.8	23.53
144w CF         3.47  11433.6	17.64