Too Much Light or not enough?

[40Gallon]

Is there a specific way to tell if a Coral is bleaching from too much light or not enough. How do you know if the lights & coral are both new?

 

[mcarroll]

A lux meter is the cheapest way to know. $15, delivered. Search for "lx1010b" - it's the standard model.

20,000 lux is "low light"; 100,000 lux is direct sunlight at sea level.

Start off with your lights at "medium" - around 40,000 lux - and only go up or down if you need to. (Anything between 20K and 80K is usually fine for most corals.)

 

[sharkboy99999]

Brown is not enough light. Bleach is to much. But you there is many other thing that can cause them to brown or bleach

 

[robert]

Corals bleach from many stressors - but it basically comes down to that they bleach whenever the zoox threaten their survival by consuming more than they contribute. Sharkboy is essentailly right - except that heat might cause a beaching event at light levels that were ok at cooler water temps.

 

[reacclimating 2 the hobby]

A lux meter is the cheapest way to know. $15, delivered. Search for "lx1010b" - it's the standard model.

20,000 lux is "low light"; 100,000 lux is direct sunlight at sea level.

Start off with your lights at "medium" - around 40,000 lux - and only go up or down if you need to. (Anything between 20K and 80K is usually fine for most corals.)

Are you saying 20k to 80k on the surface of your water? I have a lux meter, but want to make sure I'm measuring at the right place.

 

[Russ265]

ime bleaching at the base up can be either too much or too little light. -if nutrients are low

brown if nutrients are high.

 

[mcarroll]

Are you saying 20k to 80k on the surface of your water? I have a lux meter, but want to make sure I'm measuring at the right place.

Yup! At the water surface...or as close as you can.

 

[WetWhistle]

Keep a look out for a coral color being pale vs bleached as well. A coral that goes pale very quickly after making a lighting adjustment is normally from to much light. A coral that does it slowly can be from to little light, to high or low a temp or to low nutrients. Corals that are pale kind of look like a bleached corals but they still have Zooxanthellae and more color and are not white like a bleached coral because they have not expelled all the zooxanthellae.

 

[AcroFarmerRWB]

It's hard to have too much light for acros but you have to acclimate them to artificial lights, this takes a long time! I usually recommend starting them out very low then moving them up higher ever 2 weeks!

 

[mcarroll]

It's hard to have too much light for acros but you have to acclimate them to artificial lights, this takes a long time! I usually recommend starting them out very low then moving them up higher ever 2 weeks!

That sounds like one of the myths of the hobby being repeated.

It may be true, but have you ever quantified it with a lux meter or similar?

The facts would seem to be that most Acro's (and other corals) are not harvested near the surface, so are not acclimated to bright light.

That presumes we're talking about quantifiable levels of "bright" - as in around 100,000 lux (2000 PAR?), and most people don't work with the meter, instead pretending that their eyeballs can gauge brightness.

So just wondering - what level of bright are you implying? [emoji6][emoji106]

 

[AcroFarmerRWB]

I run a grow out 8'x4' with two 250w halides, 4 60" ati t5 and reef brites!
A friend of mine has a 4'X 6' grow out with 4 400w halides all running 10k halides which I don't agree with because his grow like crazy but have no color compared to mine, as long as your coral is conditioned to tank conditions your ok to run in higher lighting!

 

[AcroFarmerRWB]

I've got a colony of Oregon tort that I've had for over 5 years and it's directly under a 250w 10k

 

[AcroFarmerRWB]

And yes I use a par meter, I don't recommend lux meters they are not an accurate way to measure useable light.

 

[Russ265]

ime,
I've had corals get paler to higher lux. The more intense, the paler.... but they generally come around like any others within a couple weeks.

There has been one instance where I saw someone melt his acros and the only change was from phoenix to ushio 20ks

 

[AcroFarmerRWB]

The key to getting any coral to color under high light is slowly acclimating them to it over a long period of time and having the right spectrum.

 

[mcarroll]

And yes I use a par meter, I don't recommend lux meters they are not an accurate way to measure useable light.

I was wondering if you could tell me the number/range you are talking about?

"Bright" is practically meaningless. [emoji6]

As I indicated in the post, I am agnostic between lux and PAR. (Another myth...this time based on incorrect use cases. Lux meters work fine for our use case.)

You can work in either unit just as well with just a little understanding...

And maybe the most important point is that most people go by their eyeballs, which are much less accurate than lux meters! [emoji6][emoji106]

 

[Mykulak]

Get a PAR meter Most LFS let you borrow one. Best way to know where you should place your coral.

 

[saltyfilmfolks]

And yes I use a par meter, I don't recommend lux meters they are not an accurate way to measure useable light.

But its an inexpensive way to judge intensty. Lux is one ingredient in par.
Sorry, not judge, measure. Personally Lux meter use should be encouraged as its a quantifiable measurement of intensity and gives you a base to work from.
With it you can take the meter to the store and get a real Idea if it will work for your corals and the size of your tank... Thats HUGE for new reefers and intermediates as well.
It would also weed out those *(&%&$$*&& who sell lights that wont even grow a Xenia cuz its not bright enough even if it has the right spectrum on the box..
A par meter doesnt work well in those instances(the store or your friends house) as its results can be changed by a purple shirt.

A friend of mine has a 4'X 6' grow out with 4 400w halides all running 10k halides which I don't agree with because his grow like crazy but have no color compared to mine

And yea, he could use some spectrum. Or nutrition. or vinegar dosing.
Your spot on with the finer adjustments of par and acclimation but for the everyday reefer lights are maddening.
If I know its bright enough first, then I can work on color.

as long as your coral is conditioned to tank conditions your ok to run in higher lighting!

Agreed whole heartedly.

 

[mcarroll]

Get a PAR meter Most LFS let you borrow one. Best way to know where you should place your coral.

Lots of folks don't even have a local fish store apparently, let alone someone willing the shell out like that for a loaner.

As already mentioned a lux meter works fine for our use case and only costs about $15 delivered.

If you have, or have access to, a PAR meter, that's wonderful.

For the vast vast majority who don't, and who cannot pony up the $300, a lux meter is the ticket.

People really need to know there's no excuse for judging your lights with your eyeballs. Meters are both cheap and available - use one! [emoji3][emoji106]

 

[saltyfilmfolks]

Are you saying 20k to 80k on the surface of your water? I have a lux meter, but want to make sure I'm measuring at the right place.

Yes. at the surface of the water. But corals are pretty hardy and many do well in lower (and higher) lighting.
yes it changes growth rates and color as does spectrum and nutrition, and yes some need higher/lower light period