Estimating PAR - desk lamp LED? - The Planted Tank Forum
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 19 (permalink) Old 06-12-2019, 11:29 PM Thread Starter
Wannabe Guru
 
PTrader: (17/100%)
Join Date: Jan 2011
Location: TN
Posts: 1,811
Estimating PAR - desk lamp LED?

Are there any rough guidelines for guesstimating PAR from a desktop LED lamp? I have one of those Chinyo adjustable lamps from Staples 18" above the sand of a 7.5g shrimp tank; I'm hoping to grow fissidens on the rocks and Monte Carlo in the open spaces using light low enough that CO2/Excel is not required.

Getting back to the hobby and up to speed.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Rainer is offline  
Sponsored Links
Advertisement
 
post #2 of 19 (permalink) Old 06-13-2019, 12:32 AM
Planted Member
 
Stayinblitzed's Avatar
 
PTrader: (0/0%)
Join Date: Jun 2017
Posts: 181
I’m not sure but I’m going to guess it will not be much at all. My current led plus pros put out 70 par at the height according to the site. I can tell you it is much brighter than my led lamp
Stayinblitzed is offline  
post #3 of 19 (permalink) Old 06-13-2019, 12:48 AM
Planted Tank Guru
 
PTrader: (0/0%)
Join Date: Jun 2013
Location: WI
Posts: 10,978
Quote:
Originally Posted by Rainer View Post
Are there any rough guidelines for guesstimating PAR from a desktop LED lamp? I have one of those Chinyo adjustable lamps from Staples 18" above the sand of a 7.5g shrimp tank; I'm hoping to grow fissidens on the rocks and Monte Carlo in the open spaces using light low enough that CO2/Excel is not required.
Guesstimating is always possible ....................But you nedd "something" to go on..


Lumens/watts and possible beam angle..


Getting a beam angle isn't too difficult.
Just point it at a white sheet of paper say at 12" .If it's too wide .. bring the light down closer..
Measure diameter in the brightest area (ignore the duller yet bright outermost ring..


Get that and we can have a shot at it..

"A man with a watch knows what time it is. A man with two watches is never sure."
jeffkrol is online now  
 
post #4 of 19 (permalink) Old 06-13-2019, 03:06 AM
Algae Grower
 
Newbie Tankard's Avatar
 
PTrader: (2/100%)
Join Date: Dec 2018
Posts: 96
I use great value leds from walmart in brooder lamps and I used the might calculator on barrreport to guestinate what I had. Theres different light options there to calculate non just pick something close. For my leds I went with the eco leds or something like that. Thia seemed to work for me as I ained for right arpund 30 par which is a bit much without co2 and I got hair algea and such from too much light. I've since decreased my light.
Newbie Tankard is online now  
post #5 of 19 (permalink) Old 06-13-2019, 04:37 AM Thread Starter
Wannabe Guru
 
PTrader: (17/100%)
Join Date: Jan 2011
Location: TN
Posts: 1,811
Quote:
Originally Posted by jeffkrol View Post
....
Get that and we can have a shot at it..
Hi Jeff, after locating a second data plate with a different manufacturer's name, I found it online: here.

It's 5w and the beam is quite wide, covering all but the corners of a sheet of notebook paper at 5". There is no discernible ring at any height.

ETA: Running the numbers on the light calculator mentioned above, I get over 100 mMol at 18". That's based on the assumptions that it's one LED (there are 12 yellowish rectangles in the bulb) of BML 90 degree type running at rated size of 5w.

Getting back to the hobby and up to speed.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


Last edited by Rainer; 06-13-2019 at 04:48 AM. Reason: ...
Rainer is offline  
post #6 of 19 (permalink) Old 06-13-2019, 05:12 AM
Planted Tank Guru
 
PTrader: (0/0%)
Join Date: Jun 2013
Location: WI
Posts: 10,978
Ok assuming about 8.5" at 5" height the cone is about 90 degrees..roughly..
Sort of expected
Quote:
COLOR TEMPERATURE....5000K
LUMENS.......300
https://www.globalindustrial.com/p/e...h-5-cord-black
also sort of expected but if I didn't find actual I would prob. have assumed about 400 Lumens
1827 Lux @ 5"
30 PAR
@18"...(3ft beam spread)
About 2 PAR..

@18" you have very little PAR..
As a crazy comparison.. IF the spot size at 5" was 1" (about 12 degree beam)
1606 lumens at 18"
27 PAR and a 4" circle..


https://www.rapidtables.com/calc/lig...alculator.html
https://www.waveformlighting.com/hor...ine-calculator

60 as a lux/PAR conversion factor

Even assuming a tighter beam wouldn't get you much more..

"A man with a watch knows what time it is. A man with two watches is never sure."

Last edited by jeffkrol; 06-13-2019 at 05:22 AM. Reason: edit
jeffkrol is online now  
post #7 of 19 (permalink) Old 06-13-2019, 05:44 AM Thread Starter
Wannabe Guru
 
PTrader: (17/100%)
Join Date: Jan 2011
Location: TN
Posts: 1,811
It's surprisingly bright for such little PAR. Even lowering it to the minimum 12", it's still going to be negligible. Not sure it's worth finding something else - my old 13w Finnex CFL is too high - for the limited plant life I had in mind.

Thanks for the research, Jeff.

Getting back to the hobby and up to speed.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Rainer is offline  
post #8 of 19 (permalink) Old 06-13-2019, 01:41 PM
Planted Tank Guru
 
PTrader: (0/0%)
Join Date: Jun 2013
Location: WI
Posts: 10,978
Yea a guess would be around a 7W LED....
If "focused" on a 12 dia area should hit 35PAR
40 degree lens..

Random high cri bulb run @ 24V.........
https://www.lightology.com/index.php...SABEgI-3PD_BwE

Would work well..
Of course you need a fixture..24v supply Ldd-LH 350mA and a dimmer..

Found something... err.. wonderful (rarely use that term)
17" tall, dimmable, color adj and enough lumens..and relatively cheap..
foot print needs to be worked out theough but seems to dit

https://www.ledwholesalers.com/v2/in...product_id=592



Crazy cheap lights..
https://www.ledwholesalers.com/v2/in...product_id=217

"A man with a watch knows what time it is. A man with two watches is never sure."
jeffkrol is online now  
post #9 of 19 (permalink) Old 06-13-2019, 11:54 PM Thread Starter
Wannabe Guru
 
PTrader: (17/100%)
Join Date: Jan 2011
Location: TN
Posts: 1,811
Excellent find, Jeff - thanks! If that second joint flexes backward, it'll be a good fit for my 18"x12"x9.5"

Getting back to the hobby and up to speed.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Rainer is offline  
post #10 of 19 (permalink) Old 06-14-2019, 04:02 AM
Planted Tank Guru
 
PTrader: (0/0%)
Join Date: Jun 2013
Location: WI
Posts: 10,978
Quote:
Originally Posted by Rainer View Post
Excellent find, Jeff - thanks! If that second joint flexes backward, it'll be a good fit for my 18"x12"x9.5"

Yea.. not seeing that happen though..
122880488764
sells on the bay..

"A man with a watch knows what time it is. A man with two watches is never sure."
jeffkrol is online now  
post #11 of 19 (permalink) Old 06-18-2019, 02:33 PM Thread Starter
Wannabe Guru
 
PTrader: (17/100%)
Join Date: Jan 2011
Location: TN
Posts: 1,811
Yeah, that's probably not going to work with the full baseplate in the mix. Tank is 18" long, so it's likely to be rather off-center - light is coming from one of the short sides, aka peninsula style.



Another option is:https://www.amazon.com/Finnex-StingRAY-Clip-Light-Aquarium/dp/B00LMH10HC



PAR is 17 mMol @ 10" and some of it is actinic, so not close to optimum, but perhaps enough for moss and monte carlo? At this price, I could always get two, I suppose.

Getting back to the hobby and up to speed.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Rainer is offline  
post #12 of 19 (permalink) Old 06-18-2019, 03:13 PM
Planted Tank Guru
 
PTrader: (0/0%)
Join Date: Jun 2013
Location: WI
Posts: 10,978
Quote:
Originally Posted by Rainer View Post
Yeah, that's probably not going to work with the full baseplate in the mix. Tank is 18" long, so it's likely to be rather off-center - light is coming from one of the short sides, aka peninsula style.



Another option is:https://www.amazon.com/Finnex-StingRAY-Clip-Light-Aquarium/dp/B00LMH10HC



PAR is 17 mMol @ 10" and some of it is actinic, so not close to optimum, but perhaps enough for moss and monte carlo? At this price, I could always get two, I suppose.

Better...
https://www.amazon.com/Finnex-FugeRa.../dp/B00LIL7YPE

"A man with a watch knows what time it is. A man with two watches is never sure."
jeffkrol is online now  
post #13 of 19 (permalink) Old 06-18-2019, 03:32 PM Thread Starter
Wannabe Guru
 
PTrader: (17/100%)
Join Date: Jan 2011
Location: TN
Posts: 1,811
The numbers are better but it's made for siting behind one of the long walls, not a short one. The tank's sitting on a kitchen peninsula counter, so everything has to go along the short end.



Now I'm trying to find PAR on the 16" Stingray. I'm hoping for as much light as possible for the Monte Carlo without getting into medium lighting territory.

Getting back to the hobby and up to speed.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Rainer is offline  
post #14 of 19 (permalink) Old 06-18-2019, 03:39 PM
Planted Tank Guru
 
PTrader: (0/0%)
Join Date: Jun 2013
Location: WI
Posts: 10,978
I did order the desk lamp for work.. Should be here in about a week. Could give you some hard data at that time..

Anyways.. how about this:
https://shop.glassaqua.com/products/...d-light-silver
Need rimless (or notch it)

Same w/ this one:
AZOO LED FLEXI-MINI NANO LIGHT
Does swivel to the side.. but dimension???
Prob put light mostly front or back depending..

382788166994

"A man with a watch knows what time it is. A man with two watches is never sure."

Last edited by jeffkrol; 06-18-2019 at 03:43 PM. Reason: edit
jeffkrol is online now  
post #15 of 19 (permalink) Old 06-18-2019, 04:38 PM Thread Starter
Wannabe Guru
 
PTrader: (17/100%)
Join Date: Jan 2011
Location: TN
Posts: 1,811
I wish but don't think it would work. The tank is 18" long; the light 9". It's an unusual tank too, in that one of the long edges is beveled. It's a Schuber-Wright low iron from about 5 years ago.



I'm looking forward to your news about the light on order.



Thanks for all your help so far.

Getting back to the hobby and up to speed.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Rainer is offline  
Reply

Tags
None

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










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