Opinions need on LED bulb.

[dubs83]

My friend had a few of these laying around and said to go and grab two if I wanted. They are 2w x10 so 20watt LED bulbs at 5500k. Are they worth putting over a 20g long? What, if anything, would grow with these. Here's a few pics of what I'm getting

Thanks





Right is a 23 watt 6500k CFL, Left is the above mentioned LED bulb


CFL


LED

Thanks,

Paul

[JoeGREEEN]

depending on the distance above the 20L substrate yes they totaly are worth it.

with c02 you could grow probably anything providing its not too high above the tank.

[dubs83]

I'd say they're about 16 inches from the substrate but are giving me dark spots in the tank. Ill probably have to raise them or get a third one

[Hoppy]

Those are effectively spotlight bulbs, which aren't what you need for a planted tank. If you are stuck with them, you could remove the faceplate - looks like just 4 screws hold it on - and see if you can remove the optics from the LEDs. That would make them much more usable for a planted tank.

[DogFish]

Look at post #3 on my 40gl Display link in my sig line.

Depending on the coverage of the light you may need a 3rd bulb or maybe Hoppy's suggestion may work. You are not going through a lot of water depth in a 20L.

[dubs83]

Originally Posted by Hoppy

Those are effectively spotlight bulbs, which aren't what you need for a planted tank. If you are stuck with them, you could remove the faceplate - looks like just 4 screws hold it on - and see if you can remove the optics from the LEDs. That would make them much more usable for a planted tank.

By optics, you mean the plastic covers over the actual diode?

[dubs83]

Searched the serial number and found this:

https://1000bulbs.com/product/8029/LED-PAR382WFL5K.html

Anymore thoughts?

[Hoppy]

Originally Posted by dubs83

Searched the serial number and found this:

https://1000bulbs.com/product/8029/LED-PAR382WFL5K.html

Anymore thoughts?

Note that the beam angle is 30 degrees, which means the beam diameter will be about half the distance from the bulb in diameter - at 2 feet above the water, the beam will be one foot in diameter where it enters the water. Ideally the beam will be just a little less than the tank front to back dimension in diameter where it enters the water, to limit spillover light. So, for a 20 long tank, the light should be a bit more than 24 inches above the water. That puts it about 36 inches from the substrate. I don't know how much PAR you would get.