When is there TOO MUCH light?

[AMW]

I am rather new to keeping SPS and am experiencing the newbie frustrations that so many people seem to go through with SPSers.
My tank is a 34g nano, dedicated mostly to Zoos, palys, LPS, and HOPEFULLY sps as well!

The tank is well-matured and the parameters are as follows:
Alk = meq/L 3.5
ph = 8.25
PO4 = 0.01
Mag = 1500 (probably a little high)
Ca = 460
NO3 = 0.0
Temp = 81
SPG = 1.026
MH 150W - on 11 hours per day
Water changes 2 times weekly - 5 gallons each change

Now the frustration: I continue to have minimal success with SPS frags. What usually occurs is a rather quick bleaching of the coral/RTN.

QUESTION: Is there such thing as too much light for SPS, and is it possible that I may be "frying" them placing them on the top third of the rock-work???????????????? And perhaps is leaving the MHs on for 11 hours per day contributing to this?????

All feedback is welcome! Thanks.

 

[anderson99]

Can you get your hands on a par meter?

My experience has been that stonys don’t necessarily need to be hammered with light. In fact, I would argue that most acros/sps are probably more medium light corals (as opposed to high light corals).

For example, my red planet is at ~330 par and is pink, red and green. I think most reefers would agree that 300 is par is medium light.

HTH

 

[Gilby]

if you accliamte them correctly to your existing light then no, I don't think there is such thing as too much light. If you take a coral that has been under a 150w metal halide lamp and then place it at the top of the tank with a 400w metal halide then it would probably bleach and die of shock. if you place that same coral on the bottom of the tank and slowly work it's way up over the course of a few weeks then it should be fine.

 

[EvMiBo]

I think acclimating them like Gilby said is pretty important. Regardless of where I get it from, but more so if SPS is shipped to me, I will keep the frag on the bottom/sand level for at least 7 days, then move it up during the night so it can still experience the sunsrise effect from lighting. I also do a quick dip (with tank water) on all corals with revive.

I don't really think a par meter is necessary or needed. I think many corals that can withstand "medium" light can also withstand "high" lighting levels. It's just how you get them there and the surrounding parameters.

To answer your question (realting to what I just said): Of course. And yes, I've never ran MH's but 11 hours seems a little high. I run an 11 hour photoperiod with t5s but 2 of that (1 in the beginning and 1 at the end) is with only 2 out 6 bulbs on. Just take it nice and slow, your params seem fine - be sure you have an adequate amount of flow up top for the sps as well .

 

[Dustin1300]

Too much light once the water reaches 212 degrees F

Seriously, as others have said probably the coral adjusting to the light. Bleaching can occur quickly with new frags if not acclimated. IME I first determine what type of lighting the coral came from. Based on this I may leave on sand bottom longer than normal. Over the next few weeks after that I start moving up to its permanent place. Just keep a close eye on them and move down if needed. Photoperiod seems too long too. I run 2 X 250 MH 14ks 8 hours of a 12 hour period with T5s running on the first and last two hours.

 

[twiggyb]

I have a 12g nanocube with a 150w MH over it about 6 in. from the surface. If anything was higher then the sand bed it would fry, even sps. I now have it about a foot from the water and I can put stuff half way up the tank. My light runs from 8:30am to 8:30pm. I have a colony of some sort of sps in there that I keep for my filefish.

 

[mayjong]

acclimation is key.
i doubt we can provide too much light, compared to nature.
for example- if you look at a natural reef (cold or warm water) you won't see any coraline growing in the sunny areas, it only grows in the shade (in cracks, and under overhangs), yet in our tanks, it grows in the light (because we only produce the same amount as in the shade?)

 

[Dustin1300]

I would say its a certain spectrum of light or something because we have more light than in the reef's shade. I know while diving that the overhangs and shade are really dark.

 

[Rosh]

11 hours for a photoperiod is a chunk of light.
Might be a redundant amount for your corals.
I've heard of 8 hours, but 11 is a hefty amount.
Not to mention your utility bills.

 

[mayjong]

I would say its a certain spectrum of light or something because we have more light than in the reef's shade. I know while diving that the overhangs and shade are really dark.

check it out next time you dive saltwater....

 

[colgan10]

could be that the urchins are eating the coarline in the wild, many animals that live in the wild will eat it the aren't typically kept in an aquarium.

 

[customdusty]

I burn my SPS with too much light. They start to turn white in the areas with the most exposure, usually near uppermost tips and exposed areas. I also melt some of my LPS. As a result I use a shorter photoperiod and run my fixture at about 33% of capacity. In reality, I run 8x39w for 3.5 hrs a day and 4x39w for another 4 hrs. It's not a lot of watts but more than plenty for my 105g.

 

[Rosh]

I melt my LPS's too, sometimes I don't even know when there is too much light.
Because I'm so used to blasting light at my SPS's I don't realize I have LPS's and softies in the tank as well.

 

[sirreal63]

Do a Google search on coral photoinhibition, yes you can have too much light.

To the OP...not acclimating the frags to the lighting will kill them every time. Most may think that 150 watt bulbs are not very powerful, however they can be. When you add new frags to the system, pay attention to the system they came from. If the frag was getting high light it will do much better with higher light than one that wasn't.

 

[Dustin1300]

check it out next time you dive saltwater....

You are right sir. I've been thinking of a trip for the summer and need to make use of my PADI Opem Water

 

[AMW]

Thank you all for the very helpful feedback!!!

 

[Mr. Right]

Without causing a dispute, I’d like to say that light, nitrates, and phosphates, all have to be balanced to allow photosynthesis to occur. Having some nitrates and phosphates will probably help with the bleaching sps.

 

[twelvejewelz]

Without causing a dispute, I'd like to say that light, nitrates, and phosphates, all have to be balanced to allow photosynthesis to occur. Having some nitrates and phosphates will probably help with the bleaching sps.

A balance is correct but to much phosphates will cause the sps to brown not usually bleach. Alk or light is usually the bleaching culprit

 

[mayjong]

You are right sir. I've been thinking of a trip for the summer and need to make use of my PADI Opem Water

good excuse to go!
you can call it a "scientific expedition"

:spin1:

 

[Mr. Right]

A balance is correct but to much phosphates will cause the sps to brown not usually bleach. Alk or light is usually the bleaching culprit

Agreed. IMO, you want to have some phosphates & nitrates. Not too much to where it creates excess nutrients in the tank but enough to where the algae in the coral is fed. Reason I bring this up is because I've battled some issues where I had parameters in check and still my sps would bleach. I found that upping the nutrients in the tank helped remedy it.