HELP! RS Reefer 350 - what is best power I need from LEDs

[dacianb]

From your experience, what is enough power from LED lights on a RS Reefer 350 for SPS/clams level.
I am a DIY person, I can make the lights I need, but it is easy to go on too much power with LEDs. I dont have a PAR meter, so I have to rely on creatures reactions to light to see if is too much to too low.

I am considering to build either 2 modules of 180W each, or 3 modules of 130W each (those are components I already have).
Right now I am using as test a single module, powered at around 75-80W only and even my BTA went on lower side of rock under it. 2 SPS on the rock are fully open in dimmer light, but closed almost during full light blast.
Thank you for support

 

[DaveK]

.... I dont have a PAR meter, so I have to rely on creatures reactions to light to see if is too much to too low.

I am considering to build either 2 modules of 180W each, or 3 modules of 130W each ...

You really need to do a long term test, where you slowly increase the lighting. Most livestock, especially anemones and SPS corals can take massive amounts of light, but they need time to adjust. One of the nice things about LED lighting is that you can dial it back if it's a bit too bright, or you add new corals.

Just to give you an idea, I run 4 AI Hydra 52 fixtures on my 125 gal reef. They are about 135w each and I run them at about 80% of full power. Even so I have mostly soft corals. The current amount of light should be fine for SPS or clams.

Definitely go with 3 modules of 130w each. As you can see from your own picture, LEDs are very directional, sending most of the light straight down. Three modules will give you much more even lighting, even in the corners. You can also try raising the lighting a bit. This will help spread the light better, and avoids dim areas at the surface.

 

[dacianb]

Thanks Dave,

My tank is 6 months old and corals up to 2 months already in. All corals I bought from a shop with bright LEDs above shallow tanks (I think are Hydra, but I am not sure), so rather used with LEDs. FOr each new coral I dropped the light at 40W and then in course of 2 weeks rise it to 75W, but still looks like too much for some.
I read around and looked on Steve's website where recommended for a tank my size with SPS is around 250W. Probably best way to go is to have 3 x 130W - great coverage and still enough margins if see in the future that I need more power. Also I dont want to go in the opposite direction - to build an expensive, overrated system and in the end to use a fraction of it.
That cone of light looks much worse in this picture than in reality - I am using bare LEDs, not collimated and tank looks much better illuminated than the picture.

 

[DaveK]

I think your ramping up too fast for some corals. Go up about 10% and wait until they are fully spread and doing well before you go up again. This could take a month or two.

If they don't get back to fully open in a couple of weeks, then you really do have a too much light for that coral problem, and you'll wither need to keep the light at a lower level or move the coral to a dimmer location.

 

[dacianb]

I think your ramping up too fast for some corals. Go up about 10% and wait until they are fully spread and doing well before you go up again. This could take a month or two.

If they don't get back to fully open in a couple of weeks, then you really do have a too much light for that coral problem, and you'll wither need to keep the light at a lower level or move the coral to a dimmer location.

Thanks, having too much light is easy to lower (the opposite way is more difficult). It is only 75W (higher performance LEDs than typical in use and kept <40°C) but still too much. I planned initially something like 400-500W for this tank, but seems that I have to go much lower.
Today I saw the BTA moving again, in a shader area. Will have to go lower, for sure