kessil or cree, advice needed

[ReeferBill]

Ok, so I have a 24 gallon aquapod nano that I retrofit with an LED kit from rapidLED.com. It has 24 3 watt cree LEDs, 14 royal blue, 5 cool white, and 5 normal white. Its dimmable with dual drivers. I have the LEDs turned down as far as I can without them turning off, and run them for about 10 hours a day. Problem is that other than high intensity SPS, everything bleaches out and some die. I am running these LEDs at 20% or less and still burning the corals. My question is this. Since the LEDs are retrofit into the hood, they are very close to the water/corals. If I can find a way to suspend my hood, and bring them up 12-24" above the water, do you think that would help? My other option is to get a a350w kessil. My LFS has them everywhere and his corals are colorful, growing and amazing. I do plan to have mostly LPS, but some SPS at the top. Do you think the rapidLED crees I have are not as high quality as kessil, and I will have better growth and color with kessil, or do you think its just the matter that the crees are too close and intense for the corals? Please, any thoughts would be great.
Thanks.

 

[RichieT]

You can actually adjust the amperage going to the LEDs from the drivers. I believe they are suppose to run at 0.7mA. That could be causing the problem.

 

[ReeferBill]

What would changing the amperage do that the dimmers dont? I guess I am not as informed on LEDs...thanks

 

[Reefing Madness]

No, don't go with the Kessel.
Moving your LEDs up to above 12" will be a big help. Also, with that power those are at 250w Halide range, pretty high intensity for sittin em right on the tank.

 

[RichieT]

What would changing the amperage do that the dimmers dont? I guess I am not as informed on LEDs...thanks

Please someone correct me if I explain this badly. You may have done this already if you followed the Rapidled instructions. The dimmable drivers have a variable current, I seem to remember it being something like 0 - 1.5 mA. I know RapidLED suggests adjusting it to 0.7-0.8 mA so you are underdriving your LEDs. This extends the lifetime of the LED and more often than not you don't need all that current.

The dimmers are proportional to the intensity you get out of the LEDs. Most dimmers run from 0-10V. Assume that 0 is off and 10 is 100% intensity. So if you haven't adjusted your current in the driver you are essentiall running from 0mA - 1.5mA when you should be running from 0mA - 0.7mA.

 

[Texasnano]

I have a kessil a360w and it is the best light I have ever had

 

[ReeferBill]

Richie,
According to RapidLED, you only need to lower the amperage if you are using colored LEDs that require lower amperage. The LEDs I have(Blue and white) can be driven at the full amperage. I am not sure that lowering the amperage would do a lot, and I dont like the lack of shimmer with the LEDs so low.

Reefing Mad, I think I am going to raise my fixture up higher and see if it helps at all, give it a few months and see.

Texas, thanks for the reply. If raising my fixture up does not help, I will go kessil, seems like everyone has good things to say about it, but for cost effectiveness, I am going to try to raise my current fixture.

Anyone know if there is a quality or spectrum difference from kessil to cree LEDS?

 

[Liquid360]

Kessil is awesome. In house engineering and made in the USA. Worst case, they are as good as CREE. So why not them? Keep it simple.

 

[ReeferBill]

Yeah, if I would have done that first, it would have ben perfect, but I bought and built the retrofit, so I want to try to make it work for cost purposes. If I can spend $20 on hanging lights compared to $400 on a new fixture, i would rather do that. Unless the kessil will be much better. But trust me, I wish I would have just gotten the kessil to being with.

 

[jedimasterben]

Ok, so you already have a good LED fixture. Let's take care of that. Do you have any lenses on the LEDs? If so, take them off! That would be the source of your problem there.

If you're using the stock kits from Rapid, you're using Meanwell ELN-D series, which dim down to 10%. They will not shut the LEDs off without a relay.

24 LEDs is still a lot - I normally don't recommend more than 18x of your royal blue and white LEDs for the larger all-in-one tanks like that, 24 is a LOT, even at 700ma. When you dim them down, the minimum current is around 150mA, which would not be the issue with your corals bleaching, unless you have them sitting directly under the water line.

 

[ReeferBill]

Jedi,
Ok, so here are the answers. I do not have any lenses on them, as they are right behind glass(I replaced the plastic splash shield with glass). They are a few inches off the water, and I dim them as far as I can without turning off. I never lowered the amperage for the drivers because I dont have an amperage meter to check(and didnt want to buy one)
So I am thinking, should I take one full driver offline and just run 12 LEDs? If so, what color combo do you recommend? I have royal blue, cool white and normal whites to chose from.
But yes, my corals are bleaching and some are burning. My sunset monti all but died(it was near the top) and is recovering in complete shade now. But the rest of my corals do not have the vibrant colors that they should, they are all more bland. Also, am I running them too long per day? I have all 24 going for 9-11 hours a day.
Thanks

 

[Reefing Madness]

Please someone correct me if I explain this badly. You may have done this already if you followed the Rapidled instructions. The dimmable drivers have a variable current, I seem to remember it being something like 0 - 1.5 mA. I know RapidLED suggests adjusting it to 0.7-0.8 mA so you are underdriving your LEDs. This extends the lifetime of the LED and more often than not you don't need all that current.

The dimmers are proportional to the intensity you get out of the LEDs. Most dimmers run from 0-10V. Assume that 0 is off and 10 is 100% intensity. So if you haven't adjusted your current in the driver you are essentiall running from 0mA - 1.5mA when you should be running from 0mA - 0.7mA.

Correct, but if im not mistaken, for this you have to crack open the housing, thats an internal p.o.t. is it now?

 

[RichieT]

If by crack open you mean removing 4 screws then yes.

 

[ReeferBill]

yeah, its just 4 screws, but does it need to be reduced, and will that allow me to lower the brightness even more with the dimmers?

 

[jedimasterben]

Jedi,
Ok, so here are the answers. I do not have any lenses on them, as they are right behind glass(I replaced the plastic splash shield with glass). They are a few inches off the water, and I dim them as far as I can without turning off. I never lowered the amperage for the drivers because I dont have an amperage meter to check(and didnt want to buy one)
So I am thinking, should I take one full driver offline and just run 12 LEDs? If so, what color combo do you recommend? I have royal blue, cool white and normal whites to chose from.
But yes, my corals are bleaching and some are burning. My sunset monti all but died(it was near the top) and is recovering in complete shade now. But the rest of my corals do not have the vibrant colors that they should, they are all more bland. Also, am I running them too long per day? I have all 24 going for 9-11 hours a day.
Thanks

My recommendation would be to remove the cool white altogether and just run with your neutral white and royal blue. I normally recommend using a 2:4:1 ratio of neutral white to royal blue to cool blue, the cool blue adds a bit more photosynthetic spectra for peridinin (which transfers up to 95% of its energy directly to chlorophyll a), but they aren't too powerful, the reason I suggest them is because our eyes are able to see the longer wavelength better, meaning the fixture looks brighter, and gives it more of a punch to help mimic the look of a halide better.

The dimming on the LEDs should be linear, but the output of LEDs is not, since they get more efficient with less current. Still, at 150ma, you'd be hard-pressed to bleach corals unless they are right up under the light. If you started the lights out at higher amperage, you most likely did the damage to your corals then, and they will take months to fully recover. During that time, start your lighting out at the minimum current, and slowly ramp it up, adding 5% or so per week.

yeah, its just 4 screws, but does it need to be reduced, and will that allow me to lower the brightness even more with the dimmers?

Nope. The upper limit is all that changes - the minimum amperage is still determined by the default upper limit, so it will still be around 150mA.

 

[Reefing Madness]

If by crack open you mean removing 4 screws then yes.

Yea, removing the cover, not destroying the cover. =)

 

[ReeferBill]

Do you think it would be a good idea to only run 1 fixture with 7 royal blues, 3 neutral whites and 1 cool blue? I have 12 to work with. Do you suggest using any other colors like red, green or violet?

 

[jedimasterben]

Do you think it would be a good idea to only run 1 fixture with 7 royal blues, 3 neutral whites and 1 cool blue? I have 12 to work with. Do you suggest using any other colors like red, green or violet?

That might be a little too low honestly. I would use the NW and RB LEDs you have, and on the NW string add two cool blue. You'll NEED to get a multimeter and tune down the amperage if you do that, as the XP-E chip cannot handle more than 1000ma (3.4 watts). If you choose to add violet, you'd need to tune it down to 700ma, the SemiLED chip can't handle much more than that.

 

[ReeferBill]

What do you mean by too low? Is the cool blue the XP-E? Can I just keep them dimmed down under 50%, or do I HAVE to lower the amperage on the drivers?

 

[jedimasterben]

You can keep it dimmed down, but if you accidentally turn up the potentiometer too far it's possible to burn out the blue chips. I would just go ahead and pay the $20 to get a multimeter to make sure you're not going to damage anything. Tune it down to 1000ma and you'll be fine.