How to find your LED Intensity Sweet Spot??

[Stolireef]

I've got a pair of Radion XR30 G4s over my 125 and have been trying to figure out how to determine my intensity sweet spot. I think this question occurs to most reef keepers running LED's. Unlike MH or T5 lights which are pretty much on/off and photo-period, LED's give us enormous control over intensity. Note that this is neither a color nor brand question but rather, I'd like everyone's opinions on their methods of finding that perfect intensity. Since I'm in the process of dialing in the Radions, I'll probably learn quite a bit as well.

As a start, my tank is immature (about 4 months old) and is SPS dominated. There is a clam and an anemone in my future but they both need strong lights as well.

I started running my Radions at 30% about after adding my first 'tester' SPS. I've slowly ramped them up to 52%. I've increased intensity by about 2% every five days. So far the corals are very well colored and growing rapidly. The questions is how much higher should I go? My plan is to continue the ramp up but slow the increases to 2% every ten days. My real concern here is that even at ten days, will the corals have time to show problems so I can decrease the intensity.

Long post but I'd love to hear other LED users opinions on my approach and what they did.

 

[smokin'reefer]

Following. Interesting question.

 

[divetoday]

I'm definitely interested in what others say. I'm running Kessils, but have never taken them above max intensity of 55%. All corals and anemones are doing well, but I'm not seeing a ton of growth either.

 

[smokin'reefer]

I guess a par meter would be the simple answer but I've read you need to consider if you are running Ulns. I'm sure there are other considerations beside the obvious type of corals.

 

[chefjpaul]

I suggest a par meter, then leave it aone.

@saltyfilmfolks ?

 

[Bob Escher]

I'm following as a just got a Radion G4 as well three weeks ago running them at 50% right now

 

[saltyfilmfolks]

Honestly imo, it can be a bit of a guess really.
You can use a par or Lux meter and target a field of par in your tank you'd like to try. Also use copeaivles from others tanks and specs to help guess your estimate.

But once in the system you may find that it does well for pretty much everything in the tank. It's found a balance of light and nutrints and flow to grow every thing just perfectly.

I think that's the key to understanding the insanely different amounts of light you'll see folks using on the exact same coral. Not trace elements not food or aminos.

Folks chase numbers a bit too hard imo. If you really sit and think about it the numbers you'd need to run to figure out in what's going on in your tank are mind bending.

My .02

 

[Stolireef]

I completely agree that this is a tank specific determination. Turbidity of water, level of nutrients, types of coral, etc are all relevant. Since most of us don't have a par meter, and from what I've read, that is a grossly irrelevant number anyway, this thread is more about how to find your sweet spot. Do you start low and slowly ramp up, start with another successful reefers numbers and adjust (they may be really high or really low), frequency of changes of intensity, etc.

 

[ncaldwell]

I figured mine out by a red planet spa coral, it turned green because of low light. So I slowly increased the light over 2 months until it turned a nice red color and left it

 

[Stolireef]

Also, nutrient levels are a weird thing to measure. My tank has undetectable nitrates but I grow Chaeto by the pound. That means there are nutrients but the chaeto is out-competing other nuisance algae. So, can I increase my intensity?

 

[Stolireef]

Love the idea of a 'cannary' coral.

 

[saltyfilmfolks]

I completely agree that this is a tank specific determination. Turbidity of water, level of nutrients, types of coral, etc are all relevant. Since most of us don't have a par meter, and from what I've read, that is a grossly irrelevant number anyway, this thread is more about how to find your sweet spot. Do you start low and slowly ramp up, start with another successful reefers numbers and adjust (they may be really high or really low), frequency of changes of intensity, etc.

Yes
Personally I follow the masters )Sanjay tank) and use all the channels. I only balance the warm vs blue to my eye. Then focus on intensity.
I use a lux meter just to follow the intensity and adjust.

And yes start low.

 

[saltyfilmfolks]

Also, nutrient levels are a weird thing to measure. My tank has undetectable nitrates but I grow Chaeto by the pound. That means there are nutrients but the chaeto is out-competing other nuisance algae. So, can I increase my intensity?

Sure. It's your tank.

 

[Stolireef]

Snark alert, but funny.
I was really surprised that he runs at 100%. Even with his huge tank, I don't know many reef keepers that run at that intensity.

 

[jsker]

Honestly imo, it can be a bit of a guess really.
You can use a par or Lux meter and target a field of par in your tank you'd like to try. Also use copeaivles from others tanks and specs to help guess your estimate.

But once in the system you may find that it does well for pretty much everything in the tank. It's found a balance of light and nutrints and flow to grow every thing just perfectly.

I think that's the key to understanding the insanely different amounts of light you'll see folks using on the exact same coral. Not trace elements not food or aminos.

Folks chase numbers a bit too hard imo. If you really sit and think about it the numbers you'd need to run to figure out in what's going on in your tank are mind bending.

My .02

+1
I am running at 56% at present. I found anything higher started burning up my Arco.

 

[saltyfilmfolks]

Snark alert, but funny.
I was really surprised that he runs at 100%. Even with his huge tank, I don't know many reef keepers that run at that intensity.

Not intensity he has a deep tank and needs it. Spectrum.
Not too many of us are qualified to examine by Nm what a coral needs. Sanjay uses all of it not some what percentage is your magenta at. And he's actually qualified.

And its half snark. We all experiment with intensity.

 

[saltyfilmfolks]

Snark alert, but funny.
I was really surprised that he runs at 100%. Even with his huge tank, I don't know many reef keepers that run at that intensity.

He probably only has 1500 or so across the top btw Not unusual really. Old school.

 

[chefjpaul]

Love the idea of a 'cannary' coral.

Im doing just that currently with a couple testers I kept from my last tank.

I got a seyene just to measure par / lux, not for an end all - be all, but to trace measurements/ logs to adjust with, a tool.

I spend a few yesrs guessing with leds and wasn't so successful. I have learned from others, its not what they run their lights at, but what "program" / progress and tracking they do.

It truly is another parameter to test for. We run fancy graphs for our Calcium etc.. why not lights?

 

[Stolireef]

Sorry about the 'snark' comment. The smiley face was supposed to be after it. I really did think it was funny. I have a friend who is what I consider a master running a huge (750 gallons) tank and he is running the original AI Blues and Whites at 30%. Coral color is amazing and they grow out of the top of his tank. That's why I was surprised at Sanjay's intensity.

 

[saltyfilmfolks]

Sorry about the 'snark' comment. The smiley face was supposed to be after it. I really did think it was funny. I have a friend who is what I consider a master running a huge (750 gallons) tank and he is running the original AI Blues and Whites at 30%. Coral color is amazing and they grow out of the top of his tank. That's why I was surprised at Sanjay's intensity.

No it's fine. I'm glad you appreciated it in Fun.
See we all experiment.