PAR vs Distance, T5, T12, PC - New Chart - Page 2 - The Planted Tank Forum
Reply
 
LinkBack Thread Tools Display Modes
post #16 of 776 (permalink) Old 04-09-2010, 07:25 PM Thread Starter
Planted Tank Guru
 
Hoppy's Avatar
 
Join Date: Dec 2005
Location: Sacramento, CA
Posts: 20,261
Quote:
Originally Posted by insta View Post
Hoppy, if I reflectorize my little DIY LED fixture and mail it to you, would you mind running it through this same test?
I wouldn't want too accept the responsibility for getting the light back to you in operating condition. Have you looked for an aquatic plants group near you, like http://www.kcfishclub.org/ That might be a group that has a PAR meter, or one of their members may have one.

Hoppy
Hoppy is offline  
Sponsored Links
Advertisement
 
post #17 of 776 (permalink) Old 04-09-2010, 07:31 PM Thread Starter
Planted Tank Guru
 
Hoppy's Avatar
 
Join Date: Dec 2005
Location: Sacramento, CA
Posts: 20,261
Quote:
Originally Posted by SemperFish View Post
Great information for a planted noob like me. Would you answer a question for me? I plan to step up from a low tech 29 gal to a low tech 55 gal. I'm considering going with either 3x32 watt T-8s or 3x28 watt T-5 NO's. I do plan on doing an occasion excel dose, using eco complete, and low light/hard to kill plants. Would these choices be good lighting for what I want? Suggestions....Thanks in advance.
3 T8 bulbs on a 55 gallon tank, 20 inches high, or 1 T5NO bulb, should give you low light. Or 2 T5NO bulbs should give medium light. Of course if you choose to hang your light above the top of the tank, which I think is the best way to light a tank, you could use even a single T5HO light - hanging 4-5 inches above the top of the tank, to get low medium light. That gives you the best uniformity of light in the tank.

Hoppy
Hoppy is offline  
post #18 of 776 (permalink) Old 04-10-2010, 03:04 PM
Planted Tank Obsessed
 
Nate McFin's Avatar
 
Join Date: Mar 2009
Location: Grants Pass, Or
Posts: 412
Great info Hoppy.
I am not sure if I should start another thread or use this one but I am starting a 40 breeder tank. 17" Tall with a 3" or so substrate (flourite black). Lights are Catalina 3x39 T5ho ( I will most likely only use the two outer bulbs)
I will have pressurized Co2 and will be dosing EI. I plan on having a carpet (undecided between UG or HC) Stems in the back (Rotalas? Etc.)
I have flip legs for the lights but it seems hanging would be better according to the graph. if I am reading correctly (for the upper end of medium to low end of high light) I should hang the fixture 25 or so inches from the substrate. Is this right? Given my goals would you change anything regarding the set up? Change the number of bulbs used and/or the height? I really dont want algaefest 2010.
I hope you can shed some "light" on the subject, so to speak.
Thanks,
Nate
Nate McFin is offline  
post #19 of 776 (permalink) Old 04-10-2010, 06:30 PM
Planted Tank Obsessed
 
S&KGray's Avatar
 
Join Date: Nov 2008
Location: Garden Island
Posts: 399
25 inches above the substrate (11 inches above the top of the tank) looks about right to get 80 micromols of PAR at the substrate using 2 bulbs in your Catalina 3x39 T5HO fixture.

EPC #329 - VPC #59
Marina Style20
20L - P. axelrodi, C. macracanthus, H. ocellifer, T. albonubes "gold", Stiphodon sp. gobies, Sailfin mollies
16BF - T. albonubes "gold", A. dolichopterus, Ps. gertrudae "Aru II"
S&KGray is offline  
post #20 of 776 (permalink) Old 04-12-2010, 09:44 PM
Algae Grower
 
SemperFish's Avatar
 
Join Date: Mar 2010
Location: Calera, Alabama (central Alabama)
Posts: 106
Quote:
Originally Posted by Hoppy View Post
3 T8 bulbs on a 55 gallon tank, 20 inches high, or 1 T5NO bulb, should give you low light. Or 2 T5NO bulbs should give medium light. Of course if you choose to hang your light above the top of the tank, which I think is the best way to light a tank, you could use even a single T5HO light - hanging 4-5 inches above the top of the tank, to get low medium light. That gives you the best uniformity of light in the tank.
I appreciate the response. Thanks for the great info. I think I will go with the T-5 NO set up.
SemperFish is offline  
post #21 of 776 (permalink) Old 05-19-2010, 06:23 PM
Algae Grower
 
Join Date: May 2010
Location: Greenville, SC USA
Posts: 92
Quote:
Originally Posted by Hoppy View Post
I have been wondering how much PAR a typical T12 light produces. Like most everyone else I have just assumed that watts per gallon was a way to guess the light from T12 bulbs, but there is no more reason to expect that to mean anything than there is to expect it to mean anything for other bulb types. So, I decided to do some testing.

I borrowed a new two bulb 48 inch T12 light fixture from one of our local aquatic plant club members, bought a new T12 bulb - a Phillips "Natural Sunshine", 40 watt 5000K, 92 CRI bulb at HD, borrowed our club PAR meter and took some readings.
So you put one bulb in a two-bulb fixture?

I have two-bulb T12 shop lights, and when I install only one bulb, it lights up very dimly until I pop in the other bulb. Did you ever install a second bulb to see if there was a change in brightness?

I wonder if this could have given you incorrect data...
doinkmobb is offline  
post #22 of 776 (permalink) Old 05-19-2010, 09:29 PM Thread Starter
Planted Tank Guru
 
Hoppy's Avatar
 
Join Date: Dec 2005
Location: Sacramento, CA
Posts: 20,261
Quote:
Originally Posted by doinkmobb View Post
So you put one bulb in a two-bulb fixture?

I have two-bulb T12 shop lights, and when I install only one bulb, it lights up very dimly until I pop in the other bulb. Did you ever install a second bulb to see if there was a change in brightness?

I wonder if this could have given you incorrect data...
I didn't try two bulbs because I didn't want to pay for two. But, the bulb lit up as brightly as I usually see, anything but dimly. I don't recall any previous magnetic ballasted T12 fixture I have used doing what you saw, but I don't rule it out. The fixture had two power cords, two switches, so I assumed it was intended to run one bulb alone if desired.

Hoppy
Hoppy is offline  
post #23 of 776 (permalink) Old 05-20-2010, 03:26 AM
Algae Grower
 
Join Date: May 2010
Location: Greenville, SC USA
Posts: 92
Quote:
Originally Posted by Hoppy View Post
I didn't try two bulbs because I didn't want to pay for two. But, the bulb lit up as brightly as I usually see, anything but dimly. I don't recall any previous magnetic ballasted T12 fixture I have used doing what you saw, but I don't rule it out. The fixture had two power cords, two switches, so I assumed it was intended to run one bulb alone if desired.
Ah. OK. My fixture has only one power cord and no switches - it lights up when it's plugged in.

I have 4 T12 bulbs 20" above the substrate, with mylar film affixed behind the bulbs acting as crudely designed refelctors. Light output is up over the white reflectors, and heat build up under the canopy is down. The mylar is better, but I really don't know how much better.
doinkmobb is offline  
post #24 of 776 (permalink) Old 05-20-2010, 04:45 AM
Planted Tank Guru
 
xmas_one's Avatar
 
Join Date: Feb 2010
Location: Long Beach, CA
Posts: 3,337
Quote:
Originally Posted by doinkmobb View Post
So you put one bulb in a two-bulb fixture?

I have two-bulb T12 shop lights, and when I install only one bulb, it lights up very dimly until I pop in the other bulb. Did you ever install a second bulb to see if there was a change in brightness?

I wonder if this could have given you incorrect data...
That's been my experience too. I was wondering with the t12 was sooo much lower than the pc and t5.
xmas_one is offline  
post #25 of 776 (permalink) Old 05-20-2010, 04:24 PM Thread Starter
Planted Tank Guru
 
Hoppy's Avatar
 
Join Date: Dec 2005
Location: Sacramento, CA
Posts: 20,261
I did some experimenting with mylar, aluminum foil, and ordinary white paint as reflectors. To my surprise, the mylar was the least effective, the aluminum foil the most effective, but just barely better than white paint. I didn't use any special white paint, just what I had in a spray can at the time. I believe if you take care to get an ultra white paint you will get better results with that than with aluminum foil, and certainly better than with mylar. The differences I found were around 15-20% from best to worst, so the light doesn't look much different, but a PAR meter shows the differences.

Hoppy
Hoppy is offline  
post #26 of 776 (permalink) Old 06-19-2010, 10:08 PM Thread Starter
Planted Tank Guru
 
Hoppy's Avatar
 
Join Date: Dec 2005
Location: Sacramento, CA
Posts: 20,261
Today, I went back over the data I received from others about various types of bulbs and fixtures, and realized that I could characterize non-AHS PC lights as well as the AHS lights, and that I had one data point for a 150 watt HQI fixture. So, I added that to my chart of PAR vs distance, double checking how I derived that chart. It changed a little, on double checking, but not significantly. Of course the HQI line is just there for comparison, it isn't nearly good enough to use for selecting that type of fixture. The other lines should be good enough to get you into the low, medium or high light categories pretty reliably.


EDIT:
Another way to use this is to convert it into a simple table, that lets you select a lighting option based on tank height, how high you want the light to be above the top of that tank, and how much light you want. This assumes that multiple bulbs are mounted close together, reflectors are typical for that particular type of light. And, I left out the AH Supply light kits.

Hoppy

Last edited by Hoppy; 08-30-2010 at 09:50 PM.
Hoppy is offline  
post #27 of 776 (permalink) Old 06-20-2010, 12:33 AM
Wannabe Guru
 
Minsc's Avatar
 
Join Date: Jul 2006
Location: Portland, Or
Posts: 1,083
In case I haven't said it before, thank you so much for this thread Hoppy!
Minsc is offline  
post #28 of 776 (permalink) Old 06-20-2010, 02:26 AM
Algae Grower
 
Join Date: Dec 2007
Location: Plano, Tx
Posts: 142
Great work Hoppy!

How would you compare a single 2X overdriven 32W T8 bulb with a single normal T5NO bulb using an icecap reflector?

I have read a lot about T8/T12 vs T5HO but found little info on overdriven T8 vs anything.
madhatter4 is offline  
post #29 of 776 (permalink) Old 06-20-2010, 03:04 AM
Planted Tank Obsessed
 
S&KGray's Avatar
 
Join Date: Nov 2008
Location: Garden Island
Posts: 399
Quote:
Originally Posted by madhatter4 View Post
I have read a lot about T8/T12 vs T5HO but found little info on overdriven T8 vs anything.
ODNO T8 output increases over normal T8 (from GulfCoastAquarian's ODNO thread):

  • 2xODNO (2 power leads per bulb) - ~50% increase
  • 3xODNO (3 power leads per bulb) - ~75% increase
  • 4xODNO (4 power leads per bulb) - ~100% increase

EPC #329 - VPC #59
Marina Style20
20L - P. axelrodi, C. macracanthus, H. ocellifer, T. albonubes "gold", Stiphodon sp. gobies, Sailfin mollies
16BF - T. albonubes "gold", A. dolichopterus, Ps. gertrudae "Aru II"
S&KGray is offline  
post #30 of 776 (permalink) Old 06-20-2010, 04:27 AM
Algae Grower
 
Join Date: Dec 2007
Location: Plano, Tx
Posts: 142
So assuming 1 T8NO@20" gives ~10par, 1 T8ODNO 2X would yield ~20par. If I also assume that 1 T5NO gives about half the par of T5HO, I would get ~30par@20" for T5NO.

The T5NO would yield ~10par more over the T8ODNO, that's not a lot but it gets onto the low light range(barley) for 20" depth.

Does this sound right?
madhatter4 is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the The Planted Tank Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome