Led questions

[tbrennan]

OK so I am looking to start a led build but I really don't know how many leds to use. And what kind to get. I have a standard 90g any info would be helpful.

 

[liverock27]

I have 2 AI Sol Blue units over my 90g and they cover it nicely.

 

[tbrennan]

What is the ratio and how many leds? Just trying to get a little info before I start buying stuff I thinkbit might be a little cheaper to get the ones from Hong Kong.

 

[jbdreefs]

I read some where that 1 led per every 10 square inches of surface space will grow anything, 1 per 15 for most anything. However, this is a general rule and doesn't consider the depth of the tank. I'm doing 72 on a 125 gallon. Why? I've read countless threads where people install 100+ 3 watt LEDs only to keep them dimmed to 60%. In my mind, There's a fine balance between the number of LEDs you need to get the right PAR and the number or LEDs you need for good coverage. I little geometry is the key to determining how many you need for good coverage. I can help if you need it. As far as how many you need for PAR?? I'm no help at the moment. My approach right now is to try what I think I can get away with and leave room for expansion if I need it.

Edit: Take a look at stevesleds.com. He has some info on how to get a certain color. It's important to consider the temperature of the white LEDs. For instance, you may want more blues if the color temp of the whites is 7500K vs 10,000K.

Hope this helps.

 

[cr500_af]

I need to look (I'm almost positive they're 1-watt)... I'm using an LED unit with 55 LEDs over a 24x24 area on my frag tank. It isn't dimmable, and I had no bleaching or other light acclimation issues when I switched to it (corals that used to be under 250w metal halides).

 

[lilrobb]

cr500_af;716501 wrote: I need to look (I'm almost positive they're 1-watt)... I'm using an LED unit with 55 LEDs over a 24x24 area on my frag tank. It isn't dimmable, and I had no bleaching or other light acclimation issues when I switched to it (corals that used to be under 250w metal halides).

If we're talking the same unit - they're 3W...

 

[tbrennan]

JBDreefs;716477 wrote: I read some where that 1 led per every 10 square inches of surface space will grow anything, 1 per 15 for most anything. However, this is a general rule and doesn't consider the depth of the tank. I'm doing 72 on a 125 gallon. Why? I've read countless threads where people install 100+ 3 watt LEDs only to keep them dimmed to 60%. In my mind, There's a fine balance between the number of LEDs you need to get the right PAR and the number or LEDs you need for good coverage. I little geometry is the key to determining how many you need for good coverage. I can help if you need it. As far as how many you need for PAR?? I'm no help at the moment. My approach right now is to try what I think I can get away with and leave room for expansion if I need it.

Edit: Take a look at stevesleds.com. He has some info on how to get a certain color. It's important to consider the temperature of the white LEDs. For instance, you may want more blues if the color temp of the whites is 7500K vs 10,000K.

Hope this helps.

Thanks for all of the info. I'm going to continue to do a little research and figure out what I need for the par I want.