How much light is too much for acropora?

[Oregon Grown Reef]

Hey @Dana Riddle, I'm going to be getting a new lighting setup for my 40 breeder. The tank will have 99% acropora. I'm using 3 Hydra 32HDs and 4 Prime HD with Luxdium "gold" clusters . I have this many lights because I want a more even spread. I can easily turn down the intensity so as to not provide too much light, but what is considered too much light? I believe I read one of your posts stating that corals can use more par from LED lights than some other sources, but what par levels are we talking? I see BRS recommends 200-350 par, but I've seen many tanks running 500+ par and their corals look great.

Should I be looking at using a more blue spectrum for a majority of the lighting schedule? I really like the whiter look, closer to the BRS recommended spectrum for the AI lights, but I want to provide the corals with the best spectrum for overall health. I also see people running schedules where the intensity fluctuates up and down during peak hours. Is this beneficial to the corals and what is an acceptable fluctuation amount?

Any and all help is greatly appreciated. Thanks in advance for your help.

-Nate

 

[wculver]

Hey @Dana Riddle, I'm going to be getting a new lighting setup for my 40 breeder. The tank will have 99% acropora. I'm using 3 Hydra 32HDs and 4 Prime HD with Luxdium "gold" clusters . I have this many lights because I want a more even spread. I can easily turn down the intensity so as to not provide too much light, but what is considered too much light? I believe I read one of your posts stating that corals can use more par from LED lights than some other sources, but what par levels are we talking? I see BRS recommends 200-350 par, but I've seen many tanks running 500+ par and their corals look great.

Should I be looking at using a more blue spectrum for a majority of the lighting schedule? I really like the whiter look, closer to the BRS recommended spectrum for the AI lights, but I want to provide the corals with the best spectrum for overall health. I also see people running schedules where the intensity fluctuates up and down during peak hours. Is this beneficial to the corals and what is an acceptable fluctuation amount?

Any and all help is greatly appreciated. Thanks in advance for your help.

-Nate

If you're doing an acro tank then lighting needs to be pretty high and naturally there will be some variation from top to bottom. The typical suggestion is to run 200 at bottom and 350 at top but this is for a more middle of the road mixed reef setup. For acros they will like the higher light so you could push it up to 450 and 300 at bottom. You'll want to play with the height of the lights to get the spread you're looking for. I personally like to have some variation so I don't have a hot spot at the top but at the same time the bottom is still conducive to growth. Usually when I get a new one I start them off at the bottom, even in the sand, for a little bit and judege how well they extend over days or weeks. Then I move then up once they start to come out. Sometimes this is quick sometimes it is not.

Just be careful with that many lights and get a par meter to work this out. I think it's going to be pretty intense light if you had them cranked up.

I believe the Hydras have a success mode where the spectrum is right and then you can tweak it above that with the blue for color to your liking. The lighting schedules will also have a fluctuation over the course of the day which you want to take advantage of and should look like a bell curve. I believe there is a starting model to go with out of the box, just start with that and adjust the intensities so that the max isn't over the 450ish mark. Personally I also mimic the moon phase because if you can get a spawning event it's super cool and you know you're doing a good job. Xtra bonus if you can raise a new coral from scratch.

 

[Oregon Grown Reef]

If you're doing an acro tank then lighting needs to be pretty high and naturally there will be some variation from top to bottom. The typical suggestion is to run 200 at bottom and 350 at top but this is for a more middle of the road mixed reef setup. For acros they will like the higher light so you could push it up to 450 and 300 at bottom. You'll want to play with the height of the lights to get the spread you're looking for. I personally like to have some variation so I don't have a hot spot at the top but at the same time the bottom is still conducive to growth. Usually when I get a new one I start them off at the bottom, even in the sand, for a little bit and judege how well they extend over days or weeks. Then I move then up once they start to come out. Sometimes this is quick sometimes it is not.

Just be careful with that many lights and get a par meter to work this out. I think it's going to be pretty intense light if you had them cranked up.

I believe the Hydras have a success mode where the spectrum is right and then you can tweak it above that with the blue for color to your liking. The lighting schedules will also have a fluctuation over the course of the day which you want to take advantage of and should look like a bell curve. I believe there is a starting model to go with out of the box, just start with that and adjust the intensities so that the max isn't over the 450ish mark. Personally I also mimic the moon phase because if you can get a spawning event it's super cool and you know you're doing a good job. Xtra bonus if you can raise a new coral from scratch.

I have the Apogee MQ 510 to measure the par and achieve even lighting. I have a pretty good idea of how I'm going to place them already based off of the BRS Hydra 32HD recommended spacing and height. The Prime HDs will be on the outer edges of the tank pointed in slightly to eliminate shadowing. I like the idea of those par numbers you posted, but I just want to be as close to 100% certain as possible. I don't really want to play around with anything. Once it is set, I'm going to leave it there.

Spawning sure would be cool, but I don't know anything about that at this point. I'm just trying to figure out how to get them to grow and stay alive. I'm fairly certain most of the acros I tried in this tank died due to not enough light. All other parameters were good. I had like 200 par at best at the top and it dropped down considerably just a few inches below. They did okay for about a month and then they'd wither away.

 

[wculver]

I have the Apogee MQ 510 to measure the par and achieve even lighting. I have a pretty good idea of how I'm going to place them already based off of the BRS Hydra 32HD recommended spacing and height. The Prime HDs will be on the outer edges of the tank pointed in slightly to eliminate shadowing. I like the idea of those par numbers you posted, but I just want to be as close to 100% certain as possible. I don't really want to play around with anything. Once it is set, I'm going to leave it there.

Spawning sure would be cool, but I don't know anything about that at this point. I'm just trying to figure out how to get them to grow and stay alive. I'm fairly certain most of the acros I tried in this tank died due to not enough light. All other parameters were good. I had like 200 par at best at the top and it dropped down considerably just a few inches below. They did okay for about a month and then they'd wither away.

Oh my, didn't mention the 200 par part from your old setup. Yeah that's not going to be intense enough. I have a 10" clam that's okay with 200 par but until he got larger it took quite a bit of provisional feeding. Something the acros can't really rely on.

Also I didn't mention it but the reduction of shadows is a really good plan and will bode well for their health. Sounded like you already know that but it's a good thing to focus on.

As for my comment on the moon phase, I think it'll be built into the controller. I'd recommend using it because it won't hurt anything. You'd essentially have a dark tank 3 days a month or so according to the moon phase. Oddly enough during those times the coral completely close and seem to "sleep" differently. Not super important though.

 

[X-37B]

I think 2 32's or 4 16hd would be all you need.
I run 2 16hds on my 20g nano cube which is half of a 40 breeder with good results. They can grow coral on the bottom.
Tank is only 7 months old.

 

[Oregon Grown Reef]

I think 2 32's or 4 16hd would be all you need.
I run 2 16hds on my 20g nano cube which is half of a 40 breeder with good results. They can grow coral on the bottom.
Tank is only 7 months old.

I'm using 3 AI Prime HD currently and I'm barely getting 200 at the top of the tank (tested with Apogee MQ510). It may work for you because you have the sides of the tank closer together and reflecting the light. That and they're the 16s. A 4th Prime may do the trick, but I can see shadowing on the rocks from the single line of lights. I want there to be a blanket of high par light. I've already got the lights. It's just a matter of how much par acropora can use and answers to the other questions I asked.

Edit: Awesome tank, BTW.

 

[X-37B]

I'm using 3 AI Prime HD currently and I'm barely getting 200 at the top of the tank (tested with Apogee MQ510). It may work for you because you have the sides of the tank closer together and reflecting the light. That and they're the 16s. A 4th Prime may do the trick, but I can see shadowing on the rocks from the single line of lights. I want there to be a blanket of high par light. I've already got the lights. It's just a matter of how much par acropora can use and answers to the other questions I asked.

Edit: Awesome tank, BTW.

Yea never checked par.
This is my 45 frag system running 316hds and my settings for both systems. Its only 12" deep.

 

[Oregon Grown Reef]

Yea never checked par.
This is my 45 frag system running 316hds and my settings for both systems. Its only 12" deep.

Nice! Great looking tanks. You definitely have that touch. Your tanks seem to be perfectly sized for these lights.

 

[X-37B]

Nice! Great looking tanks. You definitely have that touch. Your tanks seem to be perfectly sized for these lights.

Thanks. I do need to check par.
I run them on my 80g with xr15 blues and the on the 30g fuge.

 

[Oregon Grown Reef]

Thanks. I do need to check par.
I run them on my 80g with xr15 blues and the on the 30g fuge.

If you were up here in Oregon, I'd offer to come by and test it!

 

[Bpb]

I think more units is always better and I’d use everything at your disposal and just adjust overall power levels to your needs.

My approach would be to target the 200-350 par range initially, and if you want to try to drive it higher over time, ensure your flow levels, nutrients, and ph can keep up with the increased light levels.

Would likely present challenges if you run 500-1000 par with moderate flow, super low nutrients, and ph in the 7’s. I’m sure someone will chime in with an opinion to the contrary though

 

[Oregon Grown Reef]

I think more units is always better and I’d use everything at your disposal and just adjust overall power levels to your needs.

My approach would be to target the 200-350 par range initially, and if you want to try to drive it higher over time, ensure your flow levels, nutrients, and ph can keep up with the increased light levels.

Would likely present challenges if you run 500-1000 par with moderate flow, super low nutrients, and ph in the 7’s. I’m sure someone will chime in with an opinion to the contrary though

I have 2 Nero 5 pumps that provide 100x-125x turnover, so I think I'm covered there. My goal for nutrients is 10ppm nitrate and 0.06ppm-0.08ppm phosphate. I'm at a little higher than that now and using carbon dosing (vinegar) to bring it down slightly. My pH is a work in progress, but it's on the rise. I just started dosing kalkwasser again to bring it up and will continue to tinker with it until I'm closer to 8.2-8.3. Thanks for the suggestion!

 

[noopsyche]

Here is another option, with Noopsyche can grow things:

 

[Hooz]

I thought I remembered a video from a reputable source (maybe it was a BRS video where they tested the WWC tanks) where they said they would definitely aim for that 250-350 PAR level. As has been said, you can push some crazy PAR numbers, but everything else (nitrients, flow, water parameters, etc) become much more crucial.

 

[92Miata]

I think 2 32's or 4 16hd would be all you need.
I run 2 16hds on my 20g nano cube which is half of a 40 breeder with good results. They can grow coral on the bottom.
Tank is only 7 months old.

In cases where you can adjust intensity, more sources of light is always better. Less shadowing, better color, and more adjustability.


That being said OP, "acropora" isn't a thing. Each species and cultivar is different and has different needs. I've got acropora 6" deep that I'm sure would take more light, and I've got acropora 20" down sitting on the bottom that die if I move them up any. And none of them are "deepwater" (which is a nonsense term anyways).

 

[SPS2020]

Looking forward to seeing how you like the Gold Pucks.

I have two in a Hydra 26HD (modified Ultra Blue) alongside a Hydra 32HD (modified Saxbby). It will be interesting to see how Acros respond.

 

[MoreReef]

I think 2 32's or 4 16hd would be all you need.
I run 2 16hds on my 20g nano cube which is half of a 40 breeder with good results. They can grow coral on the bottom.
Tank is only 7 months old.

Rad little tank man.