How many LEDs should I use?

[TCDK]

Hi

 

I just build a 30*30*30cm tank (about 12x12x12 inch)

 

I can't find anything usefull lightning, other than LEDs, so im thinking in building a LED lamp.

 

 

How many LEDs do I have to use? and what colors? (white and blue? how many of each)

 

I found these 10mm 130000mcd

 

http://cgi.ebay.com/White-LED-Set-of-50-Xt...1QQcmdZViewItem

 

Could I use them ? (then I could use less maybe?)

 

 

Best regards

Torben

[sammydee]

I don't know what LEDs you found, but some people have had quality issues with some of the LEDs from ebay.

 

Try an ebay user called professorled, both neanderthalman andI have had excellent quality from him. They do cost a little more, but if you contact him offering to buy outside of ebay, you can get them a LOT cheaper (like half price). I did this and got 400 whites for only £40.

[TCDK]

I don't know what LEDs you found, but some people have had quality issues with some of the LEDs from ebay.

 

Try an ebay user called professorled, both neanderthalman andI have had excellent quality from him. They do cost a little more, but if you contact him offering to buy outside of ebay, you can get them a LOT cheaper (like half price). I did this and got 400 whites for only £40.

 

 

Thanks!

 

I've contacted "professorled"

 

I thougt about using 200 white LEDs @ 20.000mcd and 50 LEDs @ 8000mcd

 

Could that work out?

[neanderthalman]

Your tank is a little too big for LEDs to be a cost effective lighting source. You need to keep them fairly tightly packed in order to get nice even lighting, otherwise, you get a "checkerboard" appearance in your tank. I estimate around 1000 LEDs to light a tank with a 30cm x 30cm footprint, which is just not economical.

 

I love my little LED lit tank, but you will save some money and LOADS of labor by getting a 70W MH retrofit kit and mounting the bulb in a DIY Regent halogen pendant. Cheaper, easier, and it's a proven light source. Go with MH and you will not be disappointed.

 

Welcome to N-R

[TCDK]

Thanks!

 

What is "MH" exactly? do you have a link for it on ebay or something? never heard of it before

 

 

If other have some ideas for what I could use, then they are welcome!

 

My Lamp is 28x28 inside, so it should fit in there! and best of all, it shoulden't cost over $65

[sammydee]

MH = metal halide. Do a forum search on it.

 

Sam

[TCDK]

MH = metal halide. Do a forum search on it.

 

Sam

 

 

 

Does a 70w MH not generat a lot of heat?

[neanderthalman]

It will generate less heat than 1000 LEDs will. Either put it in a pendant or adequately ventilate your hood to prevent water heating issues. You need to ventilate LED arrays just like MH.

 

The advantage with LEDs is that you can customize the size to use less than 70W on tiny tanks. A 70W LED array will output more heat energy than a 70W MH light because of inefficiency. If someone made a 20W MH with an appropriately sized reflector, LEDs would be obsolete.