Jump to content
Top Shelf Aquatics

Retrofitted BC29 hood with LEDs and got some questions


Recommended Posts

Hi all,


I just retrofitted my BC29 hood with LEDs yesterday like many others here and have some questions.

Let me explain my setup first, which is fairly similar to many others:

- 12 Q5 coll white

- 12 Q5 royal blue

- 14" x 7.28" heatsink from heatsinkusa.com

- 2 meanwell drivers ELN-60-48P

- 4 rows by 6 colums with simple alternate pattern of whites and blues

- no lenses

- I adjusted the current to 1000mA with an ampere meter in series with LED. I have not tested the upper and lower extremes, but it seems I'm just about the middle point. So I could go up or down with the amperage. I wouldn't want to go up, but maybe down perhaps.

Now to my questions:

1. Is there a way to get the cutoff PWM to lower than about 20%-25%?? I would love to have dawn and dusk effect, but the cutoff is really high!!! When it cuts off, it is still very bright.

2. I setup to 35% PWM to start aclimatizing the corals to LED lighting. It seems that 100% is way too bright. Does anyone here uses it at 1000mA and 100% pwm?? What settings do you use in your tank?

3. If I do decide not to ever go to 1000mA and 100%, would it be better to just use lower amperage but full PWM variation or use 1000mA and set it to let's say 80%... So, in other words, which is better: 800mA and 25% to 100% PWM or 1000mA and 25% to 80% PWM??

4. The meanwell drivers burst at about 5s after power is cut off and flashes once per driver, so I'm getting one flash from white and one flash from blue. Is there a way to minimize or eliminate this issue?

5. Since the position of white and blues are different and the beams are so concentrated, I'm getting displacement on shadows, creating a ghost shadow just like those 3D movies when you watch it without glasses. What have others do to this effect? I guess I'm used to a more smooth shadow transition.

6. Would a lightly frosted like material placed in the acrylic shield impact dramatically the penetration of light in the water? My idea was to get some kind of transparency sheet and paint it with frost paint and place in the shield. That would solve my problem with the 2 distinct shadows by dispersing light before it reaches the water. By dispersing light, I'd be loosing PAR. Would this be a waste of money on LEDs and I should just get used to new shadows?


Thanks in advance for your responses.


Link to comment

hold on, lemme read this.



after reading: most of this is above my head. the only person i can think of to answer all of this is evilc66. may want to pm him or hope he chimes in.

Link to comment

1. Probably no way to do this. It's a limitation of the driver.


2. It's going to depend on what is being kept in the tank, but I'd say very few are running at 100%


3. It's not going to matter. End result from the LED is going to be the same, as will the power usage from the wall.


4. I've seen this too, and it's moderately irritating. Not sure how easy it would be to snub that in some way.


5. It's something you get used to. Reducing surface aggitation helps.


6. Any time you diffuse light, you will lose intensity. Hard to say how much, as it will depend on the method used to diffuse the light. You will lose the shimmer though.

Link to comment
  • 2 months later...

Evil, I am having the same problem. Could I add a double pole double single throw relay in that circuit having the coil on the A/C part of the Meanwells and the poles on the side of the LEDs so when the A/C get cut it cuts the signal to the LEDs? This way the link to the LEDs gets cut before the Meanwells have time to send that last bit of current causing the LEDs to flash.

Link to comment

It's not something I would recommend. There could be issues with that capacitance unloading with no load and causeing damage. If you want the LEDs off without the flash, just kill the dimmer. The driver is still running, but power draw should be minimal.

Link to comment


This topic is now archived and is closed to further replies.

  • Recommended Discussions

  • Create New...