http://www.marinedepot.com/JBJ_Nano_Glo_4_...-FIRFRL-vi.html


Does this work good? I plan to use it, since I have chambers for my nano.

I just got an e bay one I am going to use in the middle chamber. Way cheaper.......
http://cgi.ebay.com/4-LED-White-Beam-Bar-A...%3D10%26ps%3D63

Has it shown results? So it's submerssible?

How long you've had it? How hard is it to replace? My fuge is just a bunch of chaeto.

THANK YOU for this.

from the ad description:
"Complete waterproof submersible package, can be installed 50 inches deep below water surface"

Vastly different in terms of power. You are talking 4W vs. maybe 1/4W. The majority of you growth will be in close proximity to the LEDs. With the JBJ unit, the extra power penetrates deeper into the macro ball and will get more even growth.

that first one looks amazing. Does it hover above the middle compartment or how does it sit? I have the 28 gallon JBJ and have an ugly light hanging above the middle back chamber i made into a fuge but this would work amazing

It's magnetic and sits on the back glass.

Still waiting on my media rack, so I don't have it installed yet. I would take Evils word as far as power output though......
I was looking for inexpensive, so I may need buck up later, time will tell. I will also just be using chaeto in my fuge, to be honest.....I don't want it to grow fast. So maybe less power full light will be the ticket.

Regarding the JBJ unit.


Since it is external, couldn't one make an DIY LED light comparable, for a fraction the cost of $60?

The unit looks nice. But it is hidden behind the tank, who's going to see it?



These guys seem to have a good selection of high output LEDs.
http://www.ledsupply.com/led-catalog.php?g...CFRlcagodISGGnA
What kind of resisters do you use for these new LEDs?
Single gang box or a hobby box from radio shack. There is a DIY bike light made in an Altoids can here http://ledsupply.com/diy-led-projects.php .
And a DC power supply.

You can make it somewhat cheaper. Use something a little better than resistors to drive the LEDs. There are many other ways that are far better than that. Even using an LM317 in a constant current mode is better.

I have it. and i use it on my 28... had it groin cheato in th rack .... worked great... then i uped the tank and put a cpr med hob fuge... put it on that and did a ok job it just is made to be used in the the chambers for the nano cause its concentrated at one in that one chamber and doestn disperse light over a great area... my timer fryed mine so im talkin it back and gettin a new one i should have it by friday if anyone wana buy it
it will be BNIB ..from jbj... let me know if ur interested..(im gettin rid of the 28 and waitin on my 90 to finsh its cycle so i can start movin stuf..)

I've spent the better part of today ramping up the knowledge curve on these new LEDs.
Yesterday never heard of a buckpuck...but..

Isn't a buckpuck just a variable resistor(potentiometer) with a heatsink inside?

What I use to do to power low power LEDs was throw a 1k Or 2.2k resistor between it and the low voltage power supply. Just to keep it from pulling too much current and blowing. They were never really finicky about voltage.

I need to research them more obviously.
I'll get a couple and just experiment. I've got plenty of computer junk around to scrounge up power supplies and heat sinks from.

Evil, you seem to be the guru around here on the subject. Thanks for your input. Been reading mostly your links and threads.

Not quite. It is far more sofisticated than a resistor. If it was a resistor, then none of use would be paying $20 when we can get them for 20 cents.

A Buckpuck is a buck driver (as the name implies). This type of design is called a switched inductor buck DC-DC constant current regulator/driver. There are also other types of drivers called switched capacitor, and linear. The basic concept of a switched inductor driver is that you switch and inductor (that carries the current to the LED) on and off very fast. The inductor by it's nature tries to resist a change in current (the switching on and off), and as a result, ends up averaging out the current based on the switching rate. Faster switching, higher current, slower switching, lower current. This is how the current is locked down to keep the LED alive and healthy. The chip that controls all this is the secret. It is responsible for controlling the current and voltage, and saving the LEDs (and itself) in the case of something bad happening, like a short or an open circuit on the output, or a short or reverse polarity on the input. It also takes care of all the dimming. It does all this at a much higher efficiency rate than any other way to control current.

Needless to say, a resistor can't do this. For a resistor to keep current constant, it requires the voltage across it to be constant. If the input voltage changes, or the voltage drop across the LED(s) changes (which it does), the current set by the resistor changes. This can lead to some nasty issues like thermal runaway, which can easily kill LEDs.

Thanks for the ideas. For me, as long as chaeto grows, I am happy. I have just done a cheap light shinning into the back of the panel.

I am not much of a DIYer myself.

So you think the JBJ is good? Does it come w/ that acrylic thing to hold my chaeto? Kinda confused w/ the pics..

I'm using it on my modded AC70 for my refugium. It works great. The lights are housed in a rectangular box that makes the LED's face inwards. There is another magnet that goes on the inside of the refugium that helps attach the lights to the outside of the refugium. I had some macro algae before in my refugium and the 4 LED's made compact balls of algae. I replaced the algae with some chaeto and it seems to be growing pretty evenly now. The growth is strong and the light is perfect for a refugium IMHO. Hope this helps.

nope just the light with a magnet... the acrylic holder comes with the tank only the JBJ28 CF comes with it if u want more info
http://jbjlighting.com/prod-nano-glo.html

bumbity bump..