The Modified Black Box Thread

[mcarroll]

I interpret that response as "what the heck?????"

 

[reeferfoxx]

I interpret that response as "what the heck?????"

I know. I don't know what happened. I removed the lenses and this is what happened..followed by my vermiculata rtn'ing within 3 hours that thing was bone white.

 

[saltyfilmfolks]

I know. I don't know what happened. I removed the lenses and this is what happened..followed by my vermiculata rtn'ing within 3 hours that thing was bone white.

:eek::eek::eek:

Dang! So sorry the hear that. Geeesh

 

[mcarroll]

So you had 90º lenses or 60º?

And you removed them from everything but UV?

 

[reeferfoxx]

So you had 90º lenses or 60º?

And you removed them from everything but UV?

No, it was 90 and 120 deg lenses. The white(120) and black(90).


I'm using a lens to protect the UV(390nm) chips. They degrade faster with "secondary" lenses.


Underneath that lens, is a softer layer. [I'm not sure what it's called?]

(above is my test chip)

I'm comparing longevity from a normal chip to a decapped chip.

 

[mcarroll]

Hm....removing 120's is not going to do much if anything in terms of the lighting effect...the primary lenses are usually also 120º. (But not in some cases.)

Removing the 90's would cause a predicted drop of about 30% intensity.

30% is pretty significant...

One possible explanation for the reactions seen is light shock.

We usually only think about light increases causing problems, but drops in light intensity and even changes in light spectra can have similar effects.

Changing just a few emitters per week might have made a difference in the reaction of corals.

BTW if those are sweepers, then that kinda validates the problematic drop in intensity theory.....sweepers are a feeding response. The coral may be trying to make shift in their nutrient dependance from photosynthesis to particle feeding.

 

[Dana Riddle]

Maybe we could get a #mod to move this thread to the lighting forum and maybe @Dana Riddle can give some insight on this coral response?

As others have observed, I doubt the Acropora's mesenterial (sweeper) tentacles are due to any change in lighting but due to some sort of irritant. What I really find interesting is the change in lighting patterns due to lens removal. I have some spare lenses in the lab, would be an interesting project (where's the NoDoz, LOL.) There was a mention of cosine correction with the Seneye. I have a Seneye and asked Matthew (Seneye's engineer) about this and he said it was not cosine corrected. However, newer models might be.

 

[reeferfoxx]

There was a mention of cosine correction with the Seneye. I have a Seneye and asked Matthew (Seneye's engineer) about this and he said it was not cosine corrected. However, newer models might be.

No I think you are right. It's not cosine corrected and I think I knew that but I misspoke.

I'm going with irritant or contaminant. Not entirely sure what it could be but the rubber gloves went to the trash can.

Definitely pull out the NoDoz lol! It took me nearly three hours to swap out all 55 led chips once. ;Oldman

 

[Dana Riddle]

No I think you are right. It's not cosine corrected and I think I knew that but I misspoke.

I'm going with irritant or contaminant. Not entirely sure what it could be but the rubber gloves went to the trash can.

Definitely pull out the NoDoz lol! It took me nearly three hours to swap out all 55 led chips once. ;Oldman

Re: The effects of plastics... When I was responsible for operation of the 4 Seasons/Hualalai water systems, we had an issue with biochemical oxygen demand in some samples - it spiked suddenly. We traced the problem back to a replacement hose on one of the automated samplers, and the issue was resolved when the new hose was replaced. There was something in that plastic that contaminated a 5-gallon sample collected over a 24-hour period.

 

[Jonathan Troutt]

Nice thread you guys got here. I did quite a bit of reading before making a purchase and ended up going with a viparspectra 165w box. I am trying to find a Led layout for this light but am not having any luck. I am trying to compare it to a SB. I am going to be swapping out lens on the white channel as soon as new ones arrive. Anyone else have first hand experience with this fixture on these forums?

 

[rushbattle]

Hm....removing 120's is not going to do much if anything in terms of the lighting effect...the primary lenses are usually also 120º. (But not in some cases.)

Removing the 90's would cause a predicted drop of about 30% intensity.

30% is pretty significant...

One possible explanation for the reactions seen is light shock.

We usually only think about light increases causing problems, but drops in light intensity and even changes in light spectra can have similar effects.

Changing just a few emitters per week might have made a difference in the reaction of corals.

BTW if those are sweepers, then that kinda validates the problematic drop in intensity theory.....sweepers are a feeding response. The coral may be trying to make shift in their nutrient dependance from photosynthesis to particle feeding.

I read the same as what you are saying, so I pulled all of my lenses on my SB Basic 16s. Less than half the PAR as with the lenses. So I bought some cheap 120deg lenses from ebay. PAR jumped back up about half way, so comparing the 120/90 stock lenses to all 120 lenses I was about 30% less PAR at the same measurement points. So I am not sure how to reconcile what I measured with the theory you state. Any thoughts?

 

[Mrx7899]

Nice thread you guys got here. I did quite a bit of reading before making a purchase and ended up going with a viparspectra 165w box. I am trying to find a Led layout for this light but am not having any luck. I am trying to compare it to a SB. I am going to be swapping out lens on the white channel as soon as new ones arrive. Anyone else have first hand experience with this fixture on these forums?

I have 3 of them on my 225 they are nice lights. The only thing I don't like about them is the blue color is more like ati blue plus t5 blue. I prefer the royal blue led color. But I plan on swapping out the LED board to a sb reef board.

 

[mcarroll]

I read the same as what you are saying, so I pulled all of my lenses on my SB Basic 16s. Less than half the PAR as with the lenses. So I bought some cheap 120deg lenses from ebay. PAR jumped back up about half way, so comparing the 120/90 stock lenses to all 120 lenses I was about 30% less PAR at the same measurement points. So I am not sure how to reconcile what I measured with the theory you state. Any thoughts?

No need to reconcile...I was just talking theory and made up that number on a rational basis to help. ;)

But...

My first question would be what angle are the primary lenses?

Primaries are often 120º, but they can be whatever the mfgr spec's...so as usual in life, assuming isn't a great idea when it matters. ;) (In fact are you positive about the angle on all your secondary lenses? Especially the ones that came with the light. Trust your measurements at least as much as the sticker on the box.)

You may be able to interpret what the primary lenses are from comparing similar measurements for the secondary lenses you have. It's conceivable that the primaries are closer to 180º, so if you're curious it's a worthy question to answer IMO. ;)

This next part may not be as relevant since I suspect you actually have wider primaries, but another thing to consider is whether you're losing any more light outside the tank – aka "light spill" – than you were with the stronger, more narrow lenses. (Maybe this applies to @reeferfoxx's conversion too? Read on...thinking out loud here, so brace yourselves... :D)

If you are spilling more light outside the tank, then that's obviously reducing the amount of light inside the tank.

But if you are not spilling more light, then you know that in spite of the lens change, you're still putting the same amount of light into the tank. A seeming contradiction, but not.

Your light meter is measuring incident irradiance....which is a technical term for light coming direct from the source.

The pancake-shaped sensor on your meter will indeed be hit by less light from the source when you remove the strong lenses. Lower PAR readings would seem predictable. But what about the fact that we verified no light is escaping the system?? (Let's assume you're pulling the same watts from teh wall as well.)

How can can we not be losing light AND find that measured levels are less?

There's more light bouncing around at odd angles in the tank, and less beaming in from directly overhead.

The net amount should be close to the same as before the lens change, if you had a meter that could capture it.

If you had the meter to do that, it would be measuring scalar irradiance....which is a technical term that means "from all directions".

You'd be using a sensor something like this:

LI-193
Spherical Underwater Quantum Sensor

The LI-193 Spherical Quantum Sensor measures PAR in air or underwater from all directions at depths up to 350 meters. This sensor is useful for studies of phytoplankton, which uses radiation from all directions. The measurement is referred to as Photosynthetic Photon Flux Fluence Rate (PPFFR) or Quantum Scalar Irradiance.

In reality, when removing strong lenses you're lighting up the glass of your tank more and that glass is what's doing a lot of the reflecting. (Sand bed and anything else white too.)

It's likely that more algae will grow on the glass as a result, and that will impact the reflectivity. Upgrade you CUC and glass scraper if needed! :)

It's also glass and not a mirror (duh) so there's some loss of light through the glass during reflection....why you can see into the tank. :p :D

But if you measure that light coming through the glass from the inside, I bet it accounts for almost all the "loss in PAR" between lenses and no-lenses if you could measure "all light" in the tank.

The point?

Corals are designed to make full use of scalar irradiance – which could hypothetically be a mixed blessing during a lens switch like this.

If you've taken a coral that had deep shade on it anywhere and by this lens swap have converted that deep shade area to "low light", that would be a huge increase in photosynthesis in a part of the coral that was adapted to shade. A part like that is likely to be relatively unshielded to light AND densely populated by Symbiodinium. This can be really rough on the coral, and bleaching would be the result....dino's expelled.

I wouldn't really worry as long as 1) flow is good, 2) nutrients in the system are positive (especially P) and 3) the rest of the coral is not responding similarly. Hopefully the bleached parts of the coral will be supported by the rest of the colony until those parts can adapt to the new light situation. The bleached parts are technically now safe from further damage due to "unprotected photosynthesis".

 

[reeferfoxx]

This next part may not be as relevant since I suspect you actually have wider primaries, but another thing to consider is whether you're losing any more light outside the tank – aka "light spill" – than you were with the stronger, more narrow lenses. (Maybe this applies to @reeferfoxx's conversion too? Read on...thinking out loud here, so brace yourselves... :D)

Light spill in my test was, to say the least, a lot. I've seen videos with similar lights and similar experiment though mounting heights ranged from 2" to 8" where as mine were mounted at 9". Then consider how the seneye measures.

 

[saltyfilmfolks]

Light spill in my test was, to say the least, a lot. I've seen videos with similar lights and similar experiment though mounting heights ranged from 2" to 8" where as mine were mounted at 9". Then consider how the seneye measures.

I was going to go with the IKEA $29 lamp shade.
In my biz they call it a topper or skirt. Reefing it’s a “floating canopy”. Lol.

I like that mount though. My vintage Mole Richardson Gobo head and chain are starting to bug me.

 

[NY_Caveman]

I was going to go with the IKEA $29 lamp shade.
In my biz they call it a topper or skirt. Reefing it’s a “floating canopy”. Lol.

I like that mount though. My vintage Mole Richardson Gobo head and chain are starting to bug me.

Good idea. I am going to try and build a “box kite” kind of lightweight canopy for mine using dowel rods and some 3D printed corner connectors I had made. Still looking at materials for the shade part. I will use the tank mounts for the LED and set the shade on it.

 

[saltyfilmfolks]

Good idea. I am going to try and build a “box kite” kind of lightweight canopy for mine using dowel rods and some 3D printed corner connectors I had made. Still looking at materials for the shade part. I will use the tank mounts for the LED and set the shade on it.

I made mine from ikea parts.
Fabric is upolstery fabric , scotch guarded and lined with Rosco Roscoflex shiny stuff.

 

[NY_Caveman]

I made mine from ikea parts.
Fabric is upolstery fabric , scotch guarded and lined with Rosco Roscoflex shiny stuff.

Thanks for that. The Scotchguard Water Sealant looks perfect.

 

[NY_Caveman]

@saltyfilmfolks what did you use to affix the Rosco pieces to the fabric? Or did you attach them to the frame?

EDIT: actually, if I recall, yours was more solid than just a frame.

 

[saltyfilmfolks]

@saltyfilmfolks what did you use to affix the Rosco pieces to the fabric? Or did you attach them to the frame?

EDIT: actually, if I recall, yours was more solid than just a frame.

Headliner glue for cars. Dm77 should work too.
If your frame is rigid , like stretching a canvas it should work fine. Mine is actually curtains, so I ran a few stiches in it to hold it. The flex pulled the glue in a couple spots.
Magic of Velcro to hold em on

One panel pulled for frame illustration.