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Mystichrome

Adding 2nd light - how to approach safely

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Mystichrome
I have a single AI prime on my IM20. Running a modified Saxby(less white). I’m adding a 2nd prime in the next couple of days after I finish building the 8020 arm.
I plan to have a buddy come over and do par testing for me after I set it up.
If I set my pars correctly do I need to run acclimation mode to adjust to the 2nd light?
I’m mainly adding the 2nd light to eliminate shadowing.
I think I’ll have the 2nd light on there a few days before he can come over to help me do the PAR.
How should I approach this without causing too much stress?
5-6 month old tank with mainly Zoa/LPS and 2 SPS.

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jservedio

You should take your current light intensity, reduce it by 60-70% and run both lights at that power. Then slowly increase it back up to 50% of your current intensity over the course of a couple months and adjust from there moving forward.  You can take PAR maps and try and match it, but you are going to be removing a ton of shadowing/shading, so even if you match the PAR in the currently well-lit areas of your tank exactly, adding that 2nd light is going to massively increase PAR in the shaded areas. If you have coral in those shady areas that are now all of the sudden receiving light you don't want to bleach them, especially if your are mainly LPS.

 

Lack of light will take months to kill your corals and they will very much tell you if they aren't getting enough light and give you lots of time to fix it. On the other hand, too much light can bleach your corals in just a matter of days and there aren't always signs they are getting too much light. Always err on the side of too little light and go slowly when increasing your lighting intensity.

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Mystichrome
58 minutes ago, jservedio said:

You should take your current light intensity, reduce it by 60-70% and run both lights at that power. Then slowly increase it back up to 50% of your current intensity over the course of a couple months and adjust from there moving forward.  You can take PAR maps and try and match it, but you are going to be removing a ton of shadowing/shading, so even if you match the PAR in the currently well-lit areas of your tank exactly, adding that 2nd light is going to massively increase PAR in the shaded areas. If you have coral in those shady areas that are now all of the sudden receiving light you don't want to bleach them, especially if your are mainly LPS.

 

Lack of light will take months to kill your corals and they will very much tell you if they aren't getting enough light and give you lots of time to fix it. On the other hand, too much light can bleach your corals in just a matter of days and there aren't always signs they are getting too much light. Always err on the side of too little light and go slowly when increasing your lighting intensity.

Thanks!


So should I just start with the reduced intensity, slowly bring it up over a few months and then do the PAR testing? I feel like if I do PAR testing now, it'll be sort of useless because my lights will be lower intensity and thus giving me inaccurate PAR for what I'd really target for?

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paulsz
8 minutes ago, Mystichrome said:

So should I just start with the reduced intensity, slowly bring it up over a few months and then do the PAR testing? I feel like if I do PAR testing now, it'll be sort of useless because my lights will be lower intensity and thus giving me inaccurate PAR for what I'd really target for?

I think you can do PAR testing at both the reduced intensity and the "end goal" intensity at once. Just adjust your lights manually to bring it to "end goal" intensity. Test PAR. Then set it at the reduced intensity. Test PAR again. 

 

I'm guessing it wouldn't take more than half an hour of "playing around" with the lights. And I don't think that'll really impact the corals if it's just half an hour at a more intense light.

 

If I'm wrong, please let me know. But I'm guessing that people who run their tanks in full blue and then turn up the whites during a tank photoshoot go through the same with no impact. A sudden jump in PAR for 15 or 20 mins (or however long they take pics for). 

 

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jservedio
52 minutes ago, paulsz said:

I think you can do PAR testing at both the reduced intensity and the "end goal" intensity at once. Just adjust your lights manually to bring it to "end goal" intensity. Test PAR. Then set it at the reduced intensity. Test PAR again. 

 

I'm guessing it wouldn't take more than half an hour of "playing around" with the lights. And I don't think that'll really impact the corals if it's just half an hour at a more intense light.

 

If I'm wrong, please let me know. But I'm guessing that people who run their tanks in full blue and then turn up the whites during a tank photoshoot go through the same with no impact. A sudden jump in PAR for 15 or 20 mins (or however long they take pics for). 

 

Playing around with your lights for a few hours isn't going to harm anything. It's way more dramatic when I turn my lights up for photography - I go from like 175 PAR on the sand to almost 600 PAR and spectrum goes from 18,000K to 12,000K with bunch ton of green and red. As long as I don't leave it like that for 2-3 days, everything is just fine. Personally, I wouldn't even bother with what the PAR is until both lights are on and each running at 50% of what the first light was running at. From there, I'd get the PAR meter and figure out where things are and then start to adjust. The PAR numbers don't really matter much now because your coverage is entirely changing.

 

For example, if one AI Prime is running at 40 watts, adding a 2nd AI Prime and running them both at 20 watts is going to put out roughly similar PAR - at least close enough for comfort. Dropping them down further to 15 watts each is going to give you probably around 25% less PAR than you had with one fixture, but far more even coverage so your average PAR levels will probably be close to the same while your peak PAR goes down. Your only concern when making big lighting changes in an otherwise perfectly healthy tank should be making sure you don't bleach anything.

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mcarroll
On 1/21/2021 at 10:41 AM, Mystichrome said:
I have a single AI prime on my IM20. Running a modified Saxby(less white). I’m adding a 2nd prime in the next couple of days after I finish building the 8020 arm.
I plan to have a buddy come over and do par testing for me after I set it up.
If I set my pars correctly do I need to run acclimation mode to adjust to the 2nd light?
I’m mainly adding the 2nd light to eliminate shadowing.
I think I’ll have the 2nd light on there a few days before he can come over to help me do the PAR.
How should I approach this without causing too much stress?
5-6 month old tank with mainly Zoa/LPS and 2 SPS.

Seems like you have a decent plan.  But a few questions first...

 

What are you water parameters like?

 

What are your current PAR or lux levels like?*

 

How have your corals been lately?  Anything worth writing home about?

 

If parameters are favorable and corals have been unstressed, I think you're all set.

 

If conditions are (or have recently been) marginal at all, then it's worth being more cautious/conservative....running acclimation mode might be helpful.

 

* You know you can use a lux meter and measure for yourself, right?  $10-20...no biggie.  And you know if you have that lux meter when your buddy with the PAR meter comes over that he can calibrate your lux meter in PAR units for you, right??  Then you'll have an accurate conversion factor to apply to all future lux measurements if you want to.  Time to order that lux meter!  😉  Did we talk about this before? Can't remember.

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Mystichrome
On 1/26/2021 at 1:53 AM, mcarroll said:

Seems like you have a decent plan.  But a few questions first...

 

What are you water parameters like?

 

SG: 1.025

Alk: 8.9

Phos:0.05-0.1 (higher end right before a WC)

Calc: 450

Mag:1350

Ph:8.0

Nitrate 10-20

On 1/26/2021 at 1:53 AM, mcarroll said:

 

What are your current PAR or lux levels like?*

No clue! Havent ever tested it!

On 1/26/2021 at 1:53 AM, mcarroll said:

 

How have your corals been lately?  Anything worth writing home about?

I would say almost all of my corals are doing well. I had low nutrients at one point and all my zoas and some corals were unhappy, but now everything seems to be doing well. Had a monti that just didnt do too well aside from that everything has been good. I had one torch that didnt make it, but the others are doing well. The one that didn't make it, I accidentally cracked the entire head in half when I tried to remove the plug it was on... so im attributing its demise to that. Took it out after it didnt look too good didnt want to risk it causing others damage.

On 1/26/2021 at 1:53 AM, mcarroll said:

 

If parameters are favorable and corals have been unstressed, I think you're all set.

So I added the 2nd light on Sunday, so its been 4 days now, started it at 40% acclimation thats set to run for 1 month. So far, nothing looks to be affected negatively but actually seeing some positives with the corals that were stuck in lower light at the edges.

On 1/26/2021 at 1:53 AM, mcarroll said:

 

If conditions are (or have recently been) marginal at all, then it's worth being more cautious/conservative....running acclimation mode might be helpful.

 

* You know you can use a lux meter and measure for yourself, right?  $10-20...no biggie.  And you know if you have that lux meter when your buddy with the PAR meter comes over that he can calibrate your lux meter in PAR units for you, right??  Then you'll have an accurate conversion factor to apply to all future lux measurements if you want to.  Time to order that lux meter!  😉  Did we talk about this before? Can't remember.

I think we did! He's coming friday so I don't think I'll be able to snag a lux meter on time 😞 

 

I was thinking... if I get it tested and set to the right settings - aka test it at what it would be running not on acclimation mode, and I get the desired PAR's, if I dont have a lux meter I wont play around with the settings anymore. The more things I have to play with the more ill fiddle with the light. I've foolishly done too many changes in the beginning and really trying to just set it and forget it for a while!

 

I'll still get a lux meter at some point tho haha

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mcarroll
1 hour ago, Mystichrome said:

I'll still get a lux meter at some point tho haha

As long as you can re-measure at the exact locations you measured with the PAR meter, with the exact light settings you had at that time, you can still make the lux-to-PAR conversion factor later.

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