PAR - how much is too much?

[lmm1967]

I have one section of one of our tanks that is over 600 - and things seem to be doing just fine. Zoas are open wide, grande palys are open all the wayWTH (took them a couple days).

It's under 14k 400w halides (with some supplemental 480ish nm LEDs ) - I thought "low light" corals would close up and beg to be moved but it seems they are enjoying it.

Anyone have experience with where it's just flat out too much light? I see all the time that LEDs can be so intense it hurts or kills coral and I'm wondering if it's the wavelengths rather than intensity .

 

[Tanster2]

Zoas and palys are a curious case when it comes to lighting. In the wild, they inhabit tide pools and coastal reefs that see great fluctuations in water level and natural PAR due to tides. They are highly adaptable.

In my short experience in the hobby, I feel like I have had a similar experience as you. Most corals will do just fine in high PAR as long as they are acclimated to some degree.

 

[ZapataInc]

@jcook54 came over my house with the PAR meter and i was getting 600+ par at the top of my tank and around 200-300 at the sand bed, and everything was fine. The zoas werent extending out but were open and looked happy. I am running 2 Hydra 52 HDs on the BRS AB+ settings. I did dial them back a little bit and need to do another PAR reading to see where im at.

 

[lmm1967]

I can say - GSP - no like the bright lights.

They're open when only the blue led strips are on - as soon as the halides come on they completely close up.

Interesting to see if they stay that way or if they'll eventually become accustomed to it. Perhaps super high par could be a way to control them.

 

[bhodges82]

There are a lot of factors that come in to play, alk level, nitrate, phosphate and coral type have a lot to do with what PAR a coral can take in my opinion. I think that if the building blocks are in abundance via the water chemistry then a higher than "normal" PAR value can become acceptable. I do also think that wavelength plays a big part as well as different wavelengths have different intensity.

 

[Adam]

Like bobby said there are a lot of factors at play.
600 at the surface isn't bad. 600 halfway down would be a bit high. If it's too much par/pur sps will bleach because they'll expel their zooxanthellae.

 

[jbartell123]

I had 150W LED in 29 gal second tank, and it was too much. Fish sought out shade. Algae went crazy. It was about half blue and half white light. I should have dialed it back, but I had to decommission the tank owing to the algae. But I do like the MaxSpect light. Designed and made in China, not cheap ($500), but really good. I just did not use it like I should have. I thought I spent all this money on a light, I should use it to its fullest. Mistake. Anyway I am still trying to figure out what to do
with that tank. It is not really made for saltwater and big rocks, but I do like having a second tank.

 

[bhodges82]

I had 150W LED in 29 gal second tank, and it was too much. Fish sought out shade. Algae went crazy. It was about half blue and half white light. I should have dialed it back, but I had to decommission the tank owing to the algae. But I do like the MaxSpect light. Designed and made in China, not cheap ($500), but really good. I just did not use it like I should have. I thought I spent all this money on a light, I should use it to its fullest. Mistake. Anyway I am still trying to figure out what to do
with that tank. It is not really made for saltwater and big rocks, but I do like having a second tank.

Set it back up and use what you have learned, don't give up on it.

 

[civics14]

I had 150W LED in 29 gal second tank, and it was too much. Fish sought out shade. Algae went crazy. It was about half blue and half white light. I should have dialed it back, but I had to decommission the tank owing to the algae. But I do like the MaxSpect light. Designed and made in China, not cheap ($500), but really good. I just did not use it like I should have. I thought I spent all this money on a light, I should use it to its fullest. Mistake. Anyway I am still trying to figure out what to do
with that tank. It is not really made for saltwater and big rocks, but I do like having a second tank.

I am assuming you put it at 100% right when you got it? If so, yeah, you should really start low and work your way up. Is that the light you are using now?

 

[jbartell123]

The MaxSpect 150W light is now turned off on the 29. The 75 has two 50W LED lights, which is about right and 25% of what the 29 had. Adding the second 50W Actinic blue light seems to have helped eliminate the cyano, not sure why. But I had about 40% cyano rock coverage before I added that light. So now my 75 gallon tank has one mostly white 50W LED and one Actinic blue 50W LED light, and I and the fish seem happy with this. Corals are mostly ok as well.

 

[jbartell123]

I did have the MaxSpect turned all the way up. Cannot recommend this.