Too much or too little light?

Leyth · Jan 18, 2018

Hey everyone. I am noticing some bleaching in a few of my corals and I wanted to see what others think.

I have a 36" ATI 8 bulb dimmable fixture about 11 inches above the water line. About 10 inches below that is a rock that I have some SPS on. That rock is getting 250 PAR. At the top of the water line, i'm getting about 500 PAR. Here is my bulb combo:

From front to back:

Reefbrite Strip blue XHO
ATI Blue +
ATI True Actinic
BioTek Marine BTM5HO 20K LED
ATI Blue +
ATI Coral Plus
BioTek Marine BTM5HO 20K & UV LED
ATI True Actinic
ATI Blue +

Everything is running at 100% for about 6 hours with 2 hour ramp up and ramp down periods. A total of 10 hours of lighting. The PAR measurements were done in the middle of the 6 hour 100% period.

I feel like this is low PAR, but I've also read that the blue spectrum isn't picked up on a PAR meter very well. If this is the case, could I potentially be providing too much light to my tank?

Edit: Added more details:

Haha, alright alright, I should have included those details

1 coral that is showing signs of bleaching randomly in the middle of a few branches and it has been in the tank since the start. It's a purple stylo
2 corals that are showing signs of bleaching are sitting right at 250 PAR and they're monti's. 1 WWC grafted, 1 Tequila sunrise
3 SPS are in the same area getting 250 PAR, but they aren't bleaching. One is WWC Nuclear Fusion Acro and it's thriving. One is WWC Rodger Dodger Acro and it thrived at first and now it's just kind of surviving. One is a tri color dark green acro and it's thriving very well.
1 SPS is right next to the other acroporas on the next rock getting maybe 275 PAR, it's a TCK Pikachu and it's bleaching around the base. I've never seen polyp extension from this coral day or night. Every other coral has great PE.
1 SPS is getting about 125 PAR closer to the sand bed. It's a Garf Bonsai and it's doing great too.
1 Rose Bubble Tip Anemone with 2 clowns. At 200 PAR, it's doing really well, it deflates for about 10 minutes
I have a bunch of LPS on the sandbed. Acans, Hammers, Zoas, and Lobo. They are doing great.

Taken today at 3:00 PM. These numbers have been consistently like this for weeks so it's quite consistent. The tank has been up for about 9 months. However, it was an upgrade from a 17 gallon that was running for about a year. Algae issues that I have are bubble algae. I have a ton of it and there is also a film of green algae on the back wall. My tang eats it all day.

Calcium: 480
Alkalinity: 7.5
Magnesium: 1275
Nitrate: 25ppm
PH: 8.2
Salinity: 1.025
Temp: 78.3

lazlodawg · Jan 18, 2018

Questions about your water parameters incoming in 3...2...1...

SDReefer · Jan 18, 2018

Water params, how long have you had the corals, how old is your system.

Coral is 10x more likely to be killed by too much light than too little.

Greenstreet.1 · Jan 18, 2018

lazlodawg said:
Questions about your water parameters incoming in 3...2...1...

[emoji23][emoji1533]

Leyth · Jan 18, 2018

lazlodawg said:
Questions about your water parameters incoming in 3...2...1...

Haha, alright alright, I should have included those details

1 coral that is showing signs of bleaching randomly in the middle of a few branches and it has been in the tank since the start. It's a purple stylo
2 corals that are showing signs of bleaching are sitting right at 250 PAR and they're monti's. 1 WWC grafted, 1 Tequila sunrise
3 SPS are in the same area getting 250 PAR, but they aren't bleaching. One is WWC Nuclear Fusion Acro and it's thriving. One is WWC Rodger Dodger Acro and it thrived at first and now it's just kind of surviving. One is a tri color dark green acro and it's thriving very well.
1 SPS is right next to the other acroporas on the next rock getting maybe 275 PAR, it's a TCK Pikachu and it's bleaching around the base. I've never seen polyp extension from this coral day or night. Every other coral has great PE.
1 SPS is getting about 125 PAR closer to the sand bed. It's a Garf Bonsai and it's doing great too.
1 Rose Bubble Tip Anemone with 2 clowns. At 200 PAR, it's doing really well, it deflates for about 10 minutes
I have a bunch of LPS on the sandbed. Acans, Hammers, Zoas, and Lobo. They are doing great.

Taken today at 3:00 PM. These numbers have been consistently like this for weeks so it's quite consistent. The tank has been up for about 9 months. However, it was an upgrade from a 17 gallon that was running for about a year. Algae issues that I have are bubble algae. I have a ton of it and there is also a film of green algae on the back wall. My tang eats it all day.

Calcium: 480
Alkalinity: 7.5
Magnesium: 1275
Nitrate: 25ppm
PH: 8.2
Salinity: 1.025
Temp: 78.3

Dana Riddle · Jan 19, 2018

No questions about water quality from me.

But I do want to know about your PAR meter. LiCors have a manual correction factor for the immersion effect, while Apogees might or might not have an automatic or manual correction. Of course, they offer two sensors - one is better for LEDs than the other. Also, Apogee recently recalled some of their meters due to a manufacturing defect. So, if you don't mind sharing details, we can wade through all this. Of course, you might have done so already. If this is the case - congrats!

madweazl · Jan 19, 2018

My monti cap (different sp. but still a possibility) will bleach at 250 PAR but does great at anything below that so intensity may very well be an issue for that specific coral. I didnt want to lower intensity so I moved the coral to a different area.

Leyth · Jan 19, 2018

Dana Riddle said:
No questions about water quality from me. But I do want to know about your PAR meter. LiCors have a manual correction factor for the immersion effect, while Apogees might or might not have an automatic or manual correction. Of course, they offer two sensors - one is better for LEDs than the other. Also, Apogee recently recalled some of their meters due to a manufacturing defect. So, if you don't mind sharing details, we can wade through all this. Of course, you might have done so already. If this is the case - congrats!

I actually have not looked into this aspect at all. I didn't even think about it to be honest. The PAR meter that I purchased is an Apogee SQ-420 Smart Quantum Sensor | USB Output. I ordered it September 2017.

Leyth · Jan 19, 2018

madweazl said:
My monti cap (different sp. but still a possibility) will bleach at 250 PAR but does great at anything below that so intensity may very well be an issue for that specific coral. I didnt want to lower intensity so I moved the coral to a different area.

Hmm, so maybe I was giving those corals too much light then.

A. grandis · Jan 19, 2018

Leyth said:
Hey everyone. I am noticing some bleaching in a few of my corals and I wanted to see what others think.

I have a 36" ATI 8 bulb dimmable fixture about 11 inches above the water line. About 10 inches below that is a rock that I have some SPS on. That rock is getting 250 PAR. At the top of the water line, i'm getting about 500 PAR. Here is my bulb combo:

From front to back:

Reefbrite Strip blue XHO
ATI Blue +
ATI True Actinic
BioTek Marine BTM5HO 20K LED
ATI Blue +
ATI Coral Plus
BioTek Marine BTM5HO 20K & UV LED
ATI True Actinic
ATI Blue +

Everything is running at 100% for about 6 hours with 2 hour ramp up and ramp down periods. A total of 10 hours of lighting. The PAR measurements were done in the middle of the 6 hour 100% period.

I feel like this is low PAR, but I've also read that the blue spectrum isn't picked up on a PAR meter very well. If this is the case, could I potentially be providing too much light to my tank?

Edit: Added more details:

Haha, alright alright, I should have included those details

1 coral that is showing signs of bleaching randomly in the middle of a few branches and it has been in the tank since the start. It's a purple stylo
2 corals that are showing signs of bleaching are sitting right at 250 PAR and they're monti's. 1 WWC grafted, 1 Tequila sunrise
3 SPS are in the same area getting 250 PAR, but they aren't bleaching. One is WWC Nuclear Fusion Acro and it's thriving. One is WWC Rodger Dodger Acro and it thrived at first and now it's just kind of surviving. One is a tri color dark green acro and it's thriving very well.
1 SPS is right next to the other acroporas on the next rock getting maybe 275 PAR, it's a TCK Pikachu and it's bleaching around the base. I've never seen polyp extension from this coral day or night. Every other coral has great PE.
1 SPS is getting about 125 PAR closer to the sand bed. It's a Garf Bonsai and it's doing great too.
1 Rose Bubble Tip Anemone with 2 clowns. At 200 PAR, it's doing really well, it deflates for about 10 minutes
I have a bunch of LPS on the sandbed. Acans, Hammers, Zoas, and Lobo. They are doing great.

Taken today at 3:00 PM. These numbers have been consistently like this for weeks so it's quite consistent. The tank has been up for about 9 months. However, it was an upgrade from a 17 gallon that was running for about a year. Algae issues that I have are bubble algae. I have a ton of it and there is also a film of green algae on the back wall. My tang eats it all day.

Calcium: 480
Alkalinity: 7.5
Magnesium: 1275
Nitrate: 25ppm
PH: 8.2
Salinity: 1.025
Temp: 78.3

As I aways say... PAR is just a part of the equation.
Numbers can give you a huge illusion and you are wasting your time looking at them!
Your LEDs are probably doing this, considering your temperature and assuming there is no chemistry provoking the bleaching!
Your algae problem is probably related to the LEDs/phosphates.
You don't need the LEDs at all. If you had all T5s it would be so great!
If you REALLY "NEED" those LEDs you will need to figure out the settings for them, so you don't loose your coals.
But this is just my personal opinion and recommendations.
Grandis.

madweazl · Jan 19, 2018

A. grandis said:
As I aways say... PAR is just a part of the equation.
Numbers can give you a huge illusion and you are wasting your time looking at them!
..
Grandis.

Dana Riddle posted some information a while back that covered photo-saturation and inhibition points for a number of corals. While I'm sure there are plenty of variables, it was right on the money for my monti cap and a reduction of just 5% in regard to intensity allowed the coral to heal up (rapidly). I think PAR measurements can be extremely valuable for things like this, transfer of corals between tanks, and/or between different light sources.

saltyfilmfolks · Jan 19, 2018

Those numbers sound low based on your equipment. IMO.
Esp if the Led is on an on off.
And yea, I could be wrong.

8 tubes at 12 in should be more than 500 par I belive.

A. grandis · Jan 19, 2018

Removing the LEDs will solve the problem.
If the T5s cover the whole aquarium, they are enough for the system and problem is solved forever.
As I've said to him, if he wants to keep those LEDs he will need to figure out all that intensity/photoperiod relationship.
The PAR numbers are great to have an idea, but won't help too much some of the LEDs' variables IMO. It's more like a hit and miss.
When you look too much into numbers you kinda trust only that and act like a blind horse, forgetting all the considerations of that particular fixture. Too much work and risk to the system. Not worthy IMO.
Besides, for what I see, Leyth isn't too much into numbers..
His choice...
Grandis.

A. grandis · Jan 19, 2018

Leyth said:
Hmm, so maybe I was giving those corals too much light then.

My dear, it's not the "amount of light" per say. It's the application and all together.
The unnecessary presence of those LEDs.
If you had only T5s, and your tank is up to 24" deep, you would be more than fine and you wouldn't need to figure out anything, but that is the world of LEDs.
Best thing to do is to put them very low and go from there if you REALLY, REALLY, REALLY want to keep the LEDs over the tank.
Grandis.

madweazl · Jan 19, 2018

A. grandis said:
My dear, it's not the "amount of light" per say. It's the application and all together.
The unnecessary presence of those LEDs.
If you had only T5s, and your tank is up to 24" deep, you would be more than fine and you wouldn't need to figure out anything, but that is the world of LEDs.
Best thing to do is to put them very low and go from there if you REALLY, REALLY, REALLY want to keep the LEDs over the tank.
Grandis.

If it has nothing to do with the "amount of light," why lower the corals?

A. grandis · Jan 19, 2018

madweazl said:
Dana Riddle posted some information a while back that covered photo-saturation and inhibition points for a number of corals. While I'm sure there are plenty of variables, it was right on the money for my monti cap and a reduction of just 5% in regard to intensity allowed the coral to heal up (rapidly). I think PAR measurements can be extremely valuable for things like this, transfer of corals between tanks, and/or between different light sources.

Yeah, of course PAR helps. You were fortunate to figure out your 5% before loosing your corals though.
Not everyone had the same luck. The variables will play that way. That's my point.
Enjoy.
Grandis.

A. grandis · Jan 19, 2018

madweazl said:
If it has nothing to do with the "amount of light," why lower the corals?

I was referring to the LEDs, not the corals. Sorry about that.
And yes, those LEDs are the problem, of course it's a light issue!
Grandis.

madweazl · Jan 19, 2018

A. grandis said:
Yeah, of course PAR helps. You were fortunate to figure out your 5% before loosing your corals though.
Not everyone had the same luck. The variables will play that way. That's my point.
Enjoy.
Grandis.

I was fortunate data existed and I could make an informed decision based on that data.

A. grandis · Jan 19, 2018

It's not a big deal really, it is what it is!
Take out those LEDs and put T5s or deal with them.
That's the truth!
Bring intensity to a minimum and work for days bringing up their intensity like everyone needs to do.
Don't forget the spectrum, distance of fixture from water surface and the hot spots.
I hope he has time
Grandis.