Are My Lights Too Bright

[aarbutina]

As a little bit of background I have a standard 90 gallon tank that is light by 4 Radion XR15s (which are approximately 8 inches off of the surface) running a slightly modified version of the Coral Lab Ab+ schedule (see below), which are supplemented by 2 48" ATI Coral Plus bulbs (which only run 30 minutes a day right now). At peak, the radions are hitting an intensity of 43%.

The question I have is, is it possible that this is too much light? Why am I asking this question? I have really been struggling with keeping acropora, and I can't nail down what may be going on, so I am exploring this as a possibility. Montipora, yeah I can keep those not problem (though they tend to be lowing in the tank). Zoas no problem. Chalices, favias, ricordea, euphyllia which are all on the sand bed all good there. Acropora, besides the piece of WD that I have, are gone after a couple weeks. The WD is mid level in the tank, is polyp'd up and seems to be happy, however the color is definitely off, pretty brown though shows some hints of color.

I will also add this, I have two clams in the tank, one maxima and one deresa. The maxima was initially placed on the rock work but moved itself to the sand bed and seems to be happy there. The deresa was placed on the sand bed but seems to be moving around looking for shade. Withing the past couple of days it had moved itself to a shady spot under some rock work and the euphyllia and seems to be staying put there.

Now I have measured my PAR levels using my BioTek Marine BTM3000 (link) and get around 225 and 250 PAR mid way through the tank around where the WD sits (so maybe 12" under the surface) at peak intensity and on the sand bed it is reading around 125 to 150. Sometimes I wonder if my meter is just off, and if I used a different meter would I get a different reading. I also have only used this sensor on my tank and it may make sense to reach out to a local reefer friend to see what my meter reads in their tank.

So basically, lighting experts what are your thoughts on this lighting situation?

Thanks in advance for any help or thoughts that you may be able to provide.

 

[Fishguru]

So you have any pictures of the tank fully illuminated? Did you start the acro at the bottom of the tank?

 

[Fishguru]

Do you have any palythoa? Perhaps a paly toxin?

 

[aarbutina]

So you have any pictures of the tank fully illuminated? Did you start the acro at the bottom of the tank?

I don’t have any full tank shot with it fully illuminate on me right now, put I will say it does look bright to the eye, but know nearly as bright as when I used to run a 250 watt MH over a 15 galling tank (just a little extreme). I generally start with acros on the side of the tank, 3/4 of the way down on a rack), but I am not sure that it is bright enough here.

 

[aarbutina]

Do you have any palythoa? Perhaps a paly toxin?

There are just a couple Paly polyps, 5 or 6 that weren’t there until recently. Not sure if it is enough to cause and issue but I won’t rule it out. I don’t run carbon routinely.

 

[Breadman03]

Here is some good reading and video watching. I don't know if they will help you out, but they convinced me to turn down my lights a bit with good results. You might need to do otherwise, or find that the issue is elsewhere.

https://www.advancedaquarist.com/2017/2/aafeature

https://www.reef2reef.com/threads/light-alkalinity-nutrients.319223/

 

[aarbutina]

Here is some good reading and video watching. I don't know if they will help you out, but they convinced me to turn down my lights a bit with good results. You might need to do otherwise, or find that the issue is elsewhere.

https://www.advancedaquarist.com/2017/2/aafeature

https://www.reef2reef.com/threads/light-alkalinity-nutrients.319223/

Thanks Breadman, I have watched this video a couple times, but maybe it is time to watch it again.

 

[jda]

This might be a better question in the SPS forum. Lights do matter and I do not think that Radions are great lights for acropora, but they should at least do OK. I would look to your tank first, and then hit the lights if all of this checks out. First, is your tank old enough to be growing coralline in mass quantity? I do not mean a few spots, but everywhere and growing new spots on the glass every week or two? If not, then it might be hard. A full slate of parameters and routine might be needed. Do you dose Organic Carbon, use GFO or Lan Chloride?

You could double that PAR reading and SPS would be OK.

 

[Mattrg02]

I thought mine were too strong, had acros bleaching, then rtn. It was actually not enough light. I now have my hydra26hd, over a 34g display, maxed out. NOW my acros are growing. I’m adding a second hydra26hd. You might need to turn up your lights.

 

[aarbutina]

This might be a better question in the SPS forum. Lights do matter and I do not think that Radions are great lights for acropora, but they should at least do OK. I would look to your tank first, and then hit the lights if all of this checks out. First, is your tank old enough to be growing coralline in mass quantity? I do not mean a few spots, but everywhere and growing new spots on the glass every week or two? If not, then it might be hard. A full slate of parameters and routine might be needed. Do you dose Organic Carbon, use GFO or Lan Chloride?

You could double that PAR reading and SPS would be OK.

jda, Why would you say that radions are not good lights for acropora? There are plenty of tanks that lite with strictly radions that are doing quite well.

This current tank is going on a year and a half to almost two years old and grows a good bit of coralline algae. To be fair I will say that the coralline mainly grows on the glass but if I don't stay on top of it the coralline will start blocking the view through my side panel (that I don't clean as often) in a few weeks.

Typically I keep my big there at around NSW level (ALK: ~7.5, CA: 420, and Mg: 1350). That being said I do know that I have an issue with low nutrient levels that I am trying to work on. Nitrate and Phosphate both normally read as undetectable. While currently this is thought to be the root of all evil, it wasn't that long ago that people would striving towards 0/0 tanks. Either way, it is something that I am working on and feed heavy for both the fish and corals as well as dose Acropower for aminos so there should be a good bit of available nutrients.

I don't carbon dose any longer (used to run a bio pellet reactor) as it would be counter intuitive to the desire to raise nutrient levels in the tank. I also to run GFO or lanthanum chloride (again zero phophates so no need to). Nor do I typically run carbon on my system, but may add it back in light of the palytoxin comment.

 

[aarbutina]

I thought mine were too strong, had acros bleaching, then rtn. It was actually not enough light. I now have my hydra26hd, over a 34g display, maxed out. NOW my acros are growing. I’m adding a second hydra26hd. You might need to turn up your lights.

Do you know what kind of PAR reading you were getting before you added that second Hydra26?

 

[Waters]

Do you know what kind of PAR reading you were getting before you added that second Hydra26?

I struggled with that same issue (I am running two Xr30 Gen 3 Pros over a 105 gallon) and kept trying to raise my overall intensity but could never get it above 50% without the coral reacting negatively (and that was only raising it by 1-2% every couple of weeks). The Radions are extremely strong......I am currently at 43% in a SPS dominate tank. I wouldn't worry too much about what number you are at and just watch how the coral react. Just make any changes slowly.

 

[leepink23]

jda, Why would you say that radions are not good lights for acropora? There are plenty of tanks that lite with strictly radions that are doing quite well.

This current tank is going on a year and a half to almost two years old and grows a good bit of coralline algae. To be fair I will say that the coralline mainly grows on the glass but if I don't stay on top of it the coralline will start blocking the view through my side panel (that I don't clean as often) in a few weeks.

Typically I keep my big there at around NSW level (ALK: ~7.5, CA: 420, and Mg: 1350). That being said I do know that I have an issue with low nutrient levels that I am trying to work on. Nitrate and Phosphate both normally read as undetectable. While currently this is thought to be the root of all evil, it wasn't that long ago that people would striving towards 0/0 tanks. Either way, it is something that I am working on and feed heavy for both the fish and corals as well as dose Acropower for aminos so there should be a good bit of available nutrients.

I don't carbon dose any longer (used to run a bio pellet reactor) as it would be counter intuitive to the desire to raise nutrient levels in the tank. I also to run GFO or lanthanum chloride (again zero phophates so no need to). Nor do I typically run carbon on my system, but may add it back in light of the palytoxin comment.

My radions are growing acropora, I added the diffusers and 2 coral+ and 2 blue + running 7 hrs per day. My radions are ab+ at 60% on a 48x24x30. Changing my flow to two mp40 seems to be helping as well as keep low nutrients, 0.01 phosphate and 2-3 nitrates. Now I am having trouble keeping alkalinity up because of the growth.

 

[aarbutina]

I struggled with that same issue (I am running two Xr30 Gen 3 Pros over a 105 gallon) and kept trying to raise my overall intensity but could never get it above 50% without the coral reacting negatively (and that was only raising it by 1-2% every couple of weeks). The Radions are extremely strong......I am currently at 43% in a SPS dominate tank. I wouldn't worry too much about what number you are at and just watch how the coral react. Just make any changes slowly.

There is lays the rub. Acropora are reacting negatively but I am really not sure which way I should be going. Decreasing light or increasing light.

That being said I did order a diffusers for all of my radions. Not expecting a miracle by any means, just trying to even out the lighting a little bit.

 

[Waters]

There is lays the rub. Acropora are reacting negatively but I am really not sure which way I should be going. Decreasing light or increasing light.

That being said I did order a diffusers for all of my radions. Not expecting a miracle by any means, just trying to even out the lighting a little bit.

I recommend installing the wide angle lenses also if you haven't already...that eliminates all hot spots. As far as which way to go.....Acros won't immediately react negatively to low light levels (it takes a lot longer for them to show signs of irritation) but they will react much quicker to high levels, if that makes any sense.

 

[aarbutina]

I recommend installing the wide angle lenses also if you haven't already...that eliminates all hot spots. As far as which way to go.....Acros won't immediately react negatively to low light levels (it takes a lot longer for them to show signs of irritation) but they will react much quicker to high levels, if that makes any sense.

I guess I forgot to mention it in the OP but I am running gen 4s so they already have the wider angle lenses.

My impression would be with low light the corals would brown out and you may be increased polyp extension as they try to increase their nutrient level. Since they aren’t getting it from the lights. Other than bleaching what would you expect to see from to high of light? I am seeing gradual polyp retraction and then tissue loss once the polyps have stopped showing .

 

[leepink23]

I guess I forgot to mention it in the OP but I am running gen 4s so they already have the wider angle lenses.

My impression would be with low light the corals would brown out and you may be increased polyp extension as they try to increase their nutrient level. Since they aren’t getting it from the lights. Other than bleaching what would you expect to see from to high of light? I am seeing gradual polyp retraction and then tissue loss once the polyps have stopped showing .

How much flow do you have?

 

[Waters]

I guess I forgot to mention it in the OP but I am running gen 4s so they already have the wider angle lenses.

My impression would be with low light the corals would brown out and you may be increased polyp extension as they try to increase their nutrient level. Since they aren’t getting it from the lights. Other than bleaching what would you expect to see from to high of light? I am seeing gradual polyp retraction and then tissue loss once the polyps have stopped showing .

You would definitely see polyp retraction and bleaching....I didn't realize the G4s came with wide angle lenses. Nice

 

[Oshengems]

I’m currently running my Radions gen 4 non pro at 66% intensity and I haven’t been getting good polyp extension at times I wonder if I’m giving too much light as well, mine is the typical AB+ at 100% brightness 66% intensity overal my Maxima clam is on the sand next to a rock with a Superman monti encrusting very nicely but my Acros on top have been getting less and less polyp extension I need a par meter ASAP

 

[aarbutina]

How much flow do you have?

Two MP40s, one on each end. I was previously running the short pulse 100% of the time to create a wave action. I recently switched to Reef Crest on one side to Constant Speed on the other (and this flips ever 4 hours) similar to what was discussed in the Coral Lab paper on flow.