38 Gallon DIY LED Questions
Planted Tank Forums
Your Tanks Image Hosting *Tank Tracker * Plant Profiles Fish Profiles Planted Tank Guide Photo Gallery Articles

Go Back   The Planted Tank Forum > Specific Aspects of a Planted Tank > Lighting


Reply
 
Thread Tools Display Modes
Old 01-30-2012, 03:44 AM   #1
jacc1234
Algae Grower
 
PTrader: (0/0%)
Join Date: Feb 2011
Location: Cumming, GA
Posts: 10
Default

38 Gallon DIY LED Questions


Hey,
Im starting my first planted tank and plan on using LED. For now I am holding off on CO2 so I will be sticking to low light. My tank is 36L x 12w x 20h.

In the future I might decide to add CO2 to my system so I want to be able to add more lights if necessary. I think the best way to do this would be to use less LED's and wider optics and leave room on my heatsink for additional emitters.

I also would like to keep the lights close to the top of the tank for aesthetics instead of hanging them. The XP-G seems to be recommended often and the price is good but im worried I would have to hang the fixture.

Would 6 XP-G emitters provide enough coverage? Would it be better for me to use wide optics or no optics? If the XP-G is too powerful could someone recommend 1W emitters that might be better suited?

Thanks!
jacc1234 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 01-30-2012, 07:39 PM   #2
Hoppy
Planted Tank Guru
 
Hoppy's Avatar
 
PTrader: (74/100%)
Join Date: Dec 2005
Location: Sacramento, CA
Posts: 18,813
Default

I would use 9 Cree XP-G spaced 4 inches apart in one row across the top of the tank. That should give you about 40 micromols of PAR at 350 mAmps, 70 at 700 mAmps, and 90 at 1000 mAmps. This is with no optics. You don't need optics if you have the LEDs right near the top of the tank. And, without optics the light spread will cover the whole substrate very well. Use a dimmable LED driver, so you can adjust to whatever brightness you want.

If you mount the LEDs inside an aluminum channel, about 3 inches wide by 1 inch, with 1/8 inch thick walls, that should be a good enough heatsink, with no fans needed, and the walls of the channel will prevent the bright LEDs from bothering people in the room.
__________________
Hoppy
Hoppy is online now   Reply With Quote
Old 01-31-2012, 12:55 AM   #3
jacc1234
Algae Grower
 
PTrader: (0/0%)
Join Date: Feb 2011
Location: Cumming, GA
Posts: 10
Default

Thanks for the info. If I were to add CO2 would I just double the emitters? My tank will be to the side of my TV so a raised light will be out of the question.
jacc1234 is offline   Reply With Quote
Old 01-31-2012, 01:38 AM   #4
samamorgan
Wannabe Guru
 
samamorgan's Avatar
 
PTrader: (3/100%)
Join Date: Dec 2011
Location: Seattle, WA
Posts: 1,234
Send a message via MSN to samamorgan Send a message via Skype™ to samamorgan
Default

Raised or in the hood, it doesn't matter, as long as you have something to control the light spill. You don't need more light to compensate for the addition of Co2, Co2 is a good thing no matter what your light level.
__________________
LED Lighting Compendium
20 Long Rimess w/LEDs
Quote:
Originally Posted by Ludwig van Beethoven
Don't only practice your art, but force your way into it's secrets, for it and knowledge can raise men to the divine.
samamorgan is offline   Reply With Quote
Old 01-31-2012, 01:56 AM   #5
jacc1234
Algae Grower
 
PTrader: (0/0%)
Join Date: Feb 2011
Location: Cumming, GA
Posts: 10
Default

Quote:
Originally Posted by Hoppy View Post
...
If you mount the LEDs inside an aluminum channel, about 3 inches wide by 1 inch, with 1/8 inch thick walls, that should be a good enough heatsink, with no fans needed, and the walls of the channel will prevent the bright LEDs from bothering people in the room.
Can you explain this aluminum channel to me or link a picture? Is it something like this: http://www.rapidled.com/servlet/the-...luminum/Detail
jacc1234 is offline   Reply With Quote
Old 01-31-2012, 02:04 AM   #6
nater3
Algae Grower
 
PTrader: (0/0%)
Join Date: Nov 2004
Location: regina, sk, CANADA
Posts: 102
Default

Am I ever glad it just found this thread. I am just getting back into the hobby and have decided to build a tank. (70cm x 45cm x 40cm)
I have ordered 14 cree xp-gs leds with 40 degree optics. I was worried about having enough light until I read the above. Seems I can rest easy.
nater3 is offline   Reply With Quote
Old 01-31-2012, 02:33 AM   #7
Hoppy
Planted Tank Guru
 
Hoppy's Avatar
 
PTrader: (74/100%)
Join Date: Dec 2005
Location: Sacramento, CA
Posts: 18,813
Default



This shows how to use aluminum channel extrusions as a heatsink, with the LEDs inside the channel. You would use only one piece of channel though.
__________________
Hoppy
Hoppy is online now   Reply With Quote
Old 01-31-2012, 03:27 AM   #8
samamorgan
Wannabe Guru
 
samamorgan's Avatar
 
PTrader: (3/100%)
Join Date: Dec 2011
Location: Seattle, WA
Posts: 1,234
Send a message via MSN to samamorgan Send a message via Skype™ to samamorgan
Default

Quote:
Originally Posted by Hoppy View Post
This shows how to use aluminum channel extrusions as a heatsink, with the LEDs inside the channel. You would use only one piece of channel though.
Thats pretty clean looking, hoppy. Nice.
__________________
LED Lighting Compendium
20 Long Rimess w/LEDs
Quote:
Originally Posted by Ludwig van Beethoven
Don't only practice your art, but force your way into it's secrets, for it and knowledge can raise men to the divine.
samamorgan is offline   Reply With Quote
Old 01-31-2012, 04:21 AM   #9
jacc1234
Algae Grower
 
PTrader: (0/0%)
Join Date: Feb 2011
Location: Cumming, GA
Posts: 10
Default

Thanks for the pic. DIY electronics im good at, basic hardware not so much lol. I am guessing aluminum channel is a basic construction material available at big box hardware stores.

The more I research the more I think im going to go with a simple Co2 setup out of the gate. So I assume I could have a bit more light.

LEDgroupbuy sells 6 packs of the CREE emitters and I was thinking about picking up 12 in total. Should i just tighten up the spacing a bit in one row or make two rows of 6?
jacc1234 is offline   Reply With Quote
Old 01-31-2012, 05:32 PM   #10
Hoppy
Planted Tank Guru
 
Hoppy's Avatar
 
PTrader: (74/100%)
Join Date: Dec 2005
Location: Sacramento, CA
Posts: 18,813
Default

You could think about picking up 18 total too, but with more than 9 you are very likely to be forever trying to get rid of algae problems.
__________________
Hoppy
Hoppy is online now   Reply With Quote
Old 01-31-2012, 10:30 PM   #11
jacc1234
Algae Grower
 
PTrader: (0/0%)
Join Date: Feb 2011
Location: Cumming, GA
Posts: 10
Default

Good to know. 9 LED's + Dimmer + CO2 sounds like a solid setup to me.
jacc1234 is offline   Reply With Quote
Reply

Tags
diy, led

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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

Forum Jump


All times are GMT. The time now is 06:42 AM.


Powered by vBulletin®
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright Planted Tank LLC 2012