Jump to content

How do you judge the right amount of light?


Recommended Posts

I am told that bleaching occurs where there is too much light.  Can this happen in a matter of hours, or within a day, or more slowly?  If the corals are bleaching, what else besides lighting could be the cause?

At the other end of the spectrum, what are the signs of not enough light?

When I have introduced new corals, I follow everyone's advice and start off at the sand bed.  How soon do you start moving them up? What are the repercussions of leaving the corals on the sand bed too long?

What signs do you look for when moving the coral up again?  


Link to comment
Share on other sites

Since you're a supporting member you can put your name on the list to borrow the PAR meter and check your lighting.  Then you know what the light levels are like throughout your tank and can place corals in the approximate zone.  Every coral is different.

I don't always start corals on the bottom.  I try my best to find out what light they were grown under and the distance from the light.  It gives me an idea of what type of acclimation they will need and how I need to acclimate. 

Edited by ninkylou
  • Like 1
Link to comment
Share on other sites

11 hours ago, Trailermann said:

Are you saying that if LFS sells me an acro that has been under bright light (like 350 PAR), then I can start the newly purchased stick at the top of my rocks?

Yes, I have done the PAR meter survey of my tank.

I do try and "PAR match" if possible but error on the side of slightly less light to start if I can't get a good value from the previous location.  

Link to comment
Share on other sites

On ‎8‎/‎21‎/‎2017 at 11:16 AM, Trailermann said:

That makes sense.  But I am still wondering how I can tell if a coral is not getting enough light, and how quickly too much light will kill a coral.

That Paul is the "art of reef keeping"  My experience is things will tolerate low light much longer than if you blast them with high light too quickly. Bleaching does not happen immediately but it is easy to catch when you are looking at your tank every day.  It is LPS that I have usually had issues with this. It seems like it just takes a week or 2 of too much light for an LPS to lose color and months to bring it back.

SPS when they are not getting enough light will start losing the brilliant glow that some of them get when you "cook them (put them under high par" as Caolewis likes to say.  LIke  just moving the frag rack to the back of my tank and some of the sps have lost their brilliant colors. LPS I haven't seen many issues as they tend to like lower light. Zoas when they don't get enough light will start stretching toward the light and if there is too much light they tend to shrink up. You can see all of these examples sadly at my house because I have been too busy to watch out for this. I even have a nice demonstration of bleaching happening in my frag tank.  Too bad you didn't ask at the meeting because I intentionally neglected these corals in the interest of learning ...;). 

Maybe I can use that excuse to avoid housework too... :)

  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...