How does height above the water affect PAR, or more importantly, coral health?

[BigTimeIssues]

My tank started with 2 Viper spectra fixtures over it. The tank is 30 x 30. So having 2 vipar spectras was too much IMO, but I liked the coverage. They didn't ramp, they came on for 11.5 hours a day. Blue channel was 50 percent and white channel was 1 percent. The few frags I had reacted incredible. Coloration on some frags I got, that was brown when I got them, was the best I have ever had. They was mounted about 8 inches off the water.

I did not like the lights, there was no optics. Light spill in the room was horrible. And when I get home I like for the light to be white, but I like to watch it turn blue as I rest in the evening. So when black Friday came along I ordered a neptune sky. Now I have some burnt tips, and my monti caps turned back brown at first and now they are bleaching..

Here are the details...

2 vipar spectras 165 watt.
8 inches off water
50 percent blues, 1 percent whites.
No ramping, on 11.5 hours
2 years old
No optics

-1 neptune Sky
-7 inches off water
-All channels evenly distributed during the day.
-Overall power is 70 percent.
-Ramps up and down slowly. 6 hours to 70 percent, 6 hours down. Last 2 hours the whites are phased out quicker than blue.
Stock optics
Brand new

If I move the neptune up to 11 inches off the water, should that alleviate the bleaching tips and months turning white? Even have a leptoseris on the sand turning clear/white. Or should I move it up and pull down power? Or just pull down power?

Nutrients are high. Nitrates over 25. Phosphate .25. (Not .025)

 

[Aaron75]

You should be able to adjust the light up and down to get the spread you want and then adjust the percentage

 

[BigTimeIssues]

I agree.. the spread seems good at 7 or 11 inches.. maybe a little more shadows at 11.

But how much will that height difference affect the par or better yet, will it help my corals to move the light up 4 inches. At 7 inches and 50 percent they are bleaching in the tips and months are turning white.

 

[Aaron75]

I agree.. the spread seems good at 7 or 11 inches.. maybe a little more shadows at 11.

But how much will that height difference affect the par or better yet, will it help my corals to move the light up 4 inches. At 7 inches and 50 percent they are bleaching in the tips and months are turning white.

Ok, if you like the coverage at 7 inches, leave it at 7. Instead of leaving the strength at 70% or 50%, try 30%. The only way to know the Par at their respective heights and strengths would be to measure it. Otherwise, you're just guessing based on how they respond, whether it be reaching, bleaching or whatever.

 

[oreo54]

My tank started with 2 Viper spectra fixtures over it. The tank is 30 x 30. So having 2 vipar spectras was too much IMO, but I liked the coverage. They didn't ramp, they came on for 11.5 hours a day. Blue channel was 50 percent and white channel was 1 percent. The few frags I had reacted incredible. Coloration on some frags I got, that was brown when I got them, was the best I have ever had. They was mounted about 8 inches off the water.

I did not like the lights, there was no optics. Light spill in the room was horrible. And when I get home I like for the light to be white, but I like to watch it turn blue as I rest in the evening. So when black Friday came along I ordered a neptune sky. Now I have some burnt tips, and my monti caps turned back brown at first and now they are bleaching..

Here are the details...

2 vipar spectras 165 watt.
8 inches off water
50 percent blues, 1 percent whites.
No ramping, on 11.5 hours
2 years old
No optics

-1 neptune Sky
-7 inches off water
-All channels evenly distributed during the day.
-Overall power is 70 percent.
-Ramps up and down slowly. 6 hours to 70 percent, 6 hours down. Last 2 hours the whites are phased out quicker than blue.
Stock optics
Brand new

If I move the neptune up to 11 inches off the water, should that alleviate the bleaching tips and months turning white? Even have a leptoseris on the sand turning clear/white. Or should I move it up and pull down power? Or just pull down power?

Your viparspectra we're running at like 30 watts each... 60 total watts.

The ACTUAL wattage of one at full is about 110 watts.
Meaning the blue channel was 55 watts.
At 50% that would be 27.5 watts.

Neptune sky is 200 watts. You peak wattage is 140 @. 70%.

The different optics ( vipar more focused, sky more diffuse) complicated things.

This is confusing. Did you remove the lenses that are normally on the viparspectra?

I did not like the lights, there was no optics

If so your actual par would have probably been low.
Would need real measurements but seem like you probably really boosted par in general, even w/ the ramping.

Didn't even consider the possible difference in watt efficiency between the sky and the viparspectras nor the different spectrums.

 

[BigTimeIssues]

Your viparspectra we're running at like 30 watts each... 60 total watts.

The ACTUAL wattage of one at full is about 110 watts.
Meaning the blue channel was 55 watts.
At 50% that would be 27.5 watts.

Neptune sky is 200 watts. You peak wattage is 140 @. 70%.

The different optics ( vipar more focused, sky more diffuse) complicated things.

This is confusing. Did you remove the lenses that are normally on the viparspectra?

If so your actual par would have probably been low.
Would need real measurements but seem like you probably really boosted par in general, even w/ the ramping.

Didn't even consider the possible difference in watt efficiency between the sky and the viparspectras nor the different spectrums.

The vipar spectras was bought used. I was trying to be cheap. When I got them home I figured out the optics was missing. Then after some research I found the spread without optics was 120 degrees.

 

[oreo54]

The vipar spectras was bought used. I was trying to be cheap. When I got them home I figured out the optics was missing. Then after some research I found the spread without optics was 120 degrees.

If I'm not mistaken the recessed nature of the diodes with no lenses also loses some light.

Pretty sure you had a large increase in par when you swapped for the Sky.

 

[BigTimeIssues]

If I'm not mistaken the recessed nature of the diodes with no lenses also loses some light.

Pretty sure you had a large increase in par when you swapped for the Sky.

That makes sense. I dunno why but I was thinking the 2 vipar spectras would be very intense. But after the way my corals reacted I think the par is much higher with what I have.


Another question. Even if I do get a par meter to learn the exact par reading, I would still be having to learn the corals behavior with the light. So when you guys notice lightening of the corals, do you reduce intensity, photo period, and/or change height? I don't want to just start making to many changes. Altho I have raised the fixture and backed it off 10 percent overall. After your message I really want to back off the intensity more, and shorten the photo period.

 

[MartinM]

You didn’t post your PAR before and after? If the PAR was the same, the corals likely wouldn’t have reacted badly. The animals don’t care where the light is mounted (or not).

 

[BigTimeIssues]

You didn’t post your PAR before and after? If the PAR was the same, the corals likely wouldn’t have reacted badly. The animals don’t care where the light is mounted (or not).

I don't have a par meter.

So height doesn't affect par? Is this why you say they don't care where the light is?

 

[MartinM]

It definitely does I’m just saying that how you adjust par doesn’t matter to coral.

Get a par meter, you’re having this problem because you haven’t measured your PAR

 

[BigTimeIssues]

I can't see spending that much money for a par meter that I will use once.. if that excludes me out of conversations about how corals act under differing light conditions, then I understand.

 

[Aaron75]

I can't see spending that much money for a par meter that I will use once.. if that excludes me out of conversations about how corals act under differing light conditions, then I understand.

What kind of phone do you have? There are a few apps that measure par, I've tried photone. It works but I haven't compared its readings to a real par meter. Regardless, it does give readings and will allow you to see the effects of distance on par.

 

[Aaron75]

I don't have a par meter.

So height doesn't affect par? Is this why you say they don't care where the light is?

Height does effect par, so does water. But you should in theory be able to adjust your par using percentage/strength vs height. If your light produces 300 par at 100% at 12", it might produce 450 par at 100% at 8". So in theory, you should be able to adjust the light to say 65% to achieve 300 par at 8".

 

[MartinM]

A PAR meter is essential with LED lighting. Not having one is going to lead to, well, issues like the one you’re having.

 

[BigTimeIssues]

What kind of phone do you have? There are a few apps that measure par, I've tried photone. It works but I haven't compared its readings to a real par meter. Regardless, it does give readings and will allow you to see the effects of distance on par.

Using equipment that isn't quality can be worse than not having the equipment at all. I would still be in the same situation I wouldn't know the par, and I'd still be making adjustments and watching for my coral to react.

A PAR meter is essential with LED lighting. Not having one is going to lead to, well, issues like the one you’re having.

Last time I was in the hobby, par meters was never used. And we had leds then. I looked into par meters when I first started putting this system together. The price for one that can be trusted is just too much to spend to set up my tank then let it set for months or years.

And even knowing the number I still would be looking for the reaction of the coral to see if they are getting to much or too little light.

 

[Hurricane Aquatics]

I get what you're trying to do and I understand that a PAR meter is very expensive. No one can answer your question as we would be speculating as there is no way of telling.

I have an ATI Straton that is the same shape as your Sky. If I were guessing, I would raise your sky to 13 inches above the water and adjust the overall intensity to 50 percent.

Yes, raising a light does affect PAR, but it can just as easily raise PAR or lower PAR depending on where it is measured in the tank because of light spread and refraction from the water.

You went from a 4 cylinder car to an 8 cylinder car. You don't need to step on the accelerator as hard to get where you're going. .

Try the above. Also your flow needs to be good too.

 

[BigTimeIssues]

I get what you're trying to do and I understand that a PAR meter is very expensive. No one can answer your question as we would be speculating as there is no way of telling.

I have an ATI Straton that is the same shape as your Sky. If I were guessing, I would raise your sky to 13 inches above the water and adjust the overall intensity to 50 percent.

Yes, raising a light does affect PAR, but it can just as easily raise PAR or lower PAR depending on where it is measured in the tank because of light spread and refraction from the water.

You went from a 4 cylinder car to an 8 cylinder car. You don't need to step on the accelerator as hard to get where you're going. .

Try the above. Also your flow needs to be good too.

I appreciate your response.

As far expensive, you're right.. but thats relative. I could definitely buy one.. but 550$ for something that immediately depreciates a ridiculous amount.. to use once. Maybe twice. I've looked at the cheaper ones but buying cheap test equipment is usually a bad idea. And the reviews for the lower price par meters are not good. I know some local stores offer rental but I'm out of luck there too.

I've basically done what you recommended already. This just wasn't the direction I was trying to go with the thread.. seems to be a trend here.

 

[oreo54]

I appreciate your response.

As far expensive, you're right.. but thats relative. I could definitely buy one.. but 550$ for something that immediately depreciates a ridiculous amount.. to use once. Maybe twice. I've looked at the cheaper ones but buying cheap test equipment is usually a bad idea. And the reviews for the lower price par meters are not good. I know some local stores offer rental but I'm out of luck there too.

I've basically done what you recommended already. This just wasn't the direction I was trying to go with the thread.. seems to be a trend here.

Seneye is $220 and considered good. I'd add good enough though at times a pain to use.
Still "expensive" in terms of use/$.

Coral response as a "meter" is relevant..
I would have guessed the Sky should have been started at 25%..

A $20 Lux meter is good as a comparative tool not an absolute tool as well.

 

[BigTimeIssues]

Seneye is $220 and considered good. I'd add good enough though at times a pain to use.
Still "expensive" in terms of use/$.

Coral response as a "meter" is relevant..
I would have guessed the Sky should have been started at 25%..

Heard first hand experiences of seneye being as much as 100 par off. Read alot of bad reviews as well. I almost bought the neptune sensor to use with my apex.. but the sensor is the cheaper sensor. And has bad reviews.

Cheap test equipment would put me in no better position. I'd still be running the system and making adjustments.

Thanks for the responses. How would you do the ramp? Quickly to 25 percent with a long saturation time. Or long ramps?