Sensitivity to some wavelengths of light?

[malawian]

So I am wondering if anyone else has experienced this. I would like to do more specific testing on this, but seeing that my corals are already pissed off right now, this is not the time to see what pisses corals off! This is just a hypothesis, Im not really making any claims here.

 

So I think some wavelengths may really aggrivate my corals, that is to say they are particularly sensitive to those wavelengths. Namely I think my corals are very sensitive to my true violet LEDs. I think they are 405 nm. Turning these up really made my corals angry. It was either these or some part of my 3-ups which are cyan, green, deep red (505 nm, 530 nm, and 655 nm respectively).

 

The other possibility is that with my primary blue and white channels turned down so much turning these up much has a large impact on the total amount of light (even if potential power output is miniscule compared to the primary channels). PAR meter arrives tomorrow to see if that could be true.

 

Anyone smarter than me know if something like this is possible? this is just a hypothesis, but maybe someone knows it to be true.

[Acielot]

I'll let someone with a bit more knowledge back this up but it sounds like you are really frying them by turning up those violets.

 

 

They possess more power than we can see. So even a dim light violet can put out some serious power.

 

What are the symptoms of the coral? i.e bleaching, retracted, poor pe...

[malawian]

I'll let someone with a bit more knowledge back this up but it sounds like you are really frying them by turning up those violets.

 

 

They possess more power than we can see. So even a dim light violet can put out some serious power.

 

What are the symptoms of the coral? i.e bleaching, retracted, poor pe...

 

Really poor PE (not extending day or night), losing color (but not straight bleaching, at least not yet), my favites seems to never extend feeding tentacles any more...general discontent! Some corals however, are fine or thriving, of course, just to make things more fun. water quality is perfect.

[BradVincent]

Most likely total light is the issue, and more the rate of change than the absolute amount.

 

What corals other than favites are you trying to keep? What is your tank size and total wattage? Many favites or similar corals are lower light.

 

PE is not always the same as health.

 

Color (to your eyes) is not always the same as health.

 

Your water quality is not perfect, but again, I'd worry more about about rate of change than perfection. If you are saying your water is perfect because you just did a 100% water change, the water change could be your problem.

[malawian]

no, water is perfect because I tested everything and Its exactly where it should be (ca, mg, alk all perfect, nitrate and phosphate low but not undetectable, right where I want them). I dont do that many water changes as it gets pricey on a 100g system.

 

I keep SPS and LPS, primarily SPS. Tank is 75g display, wattage isnt a very helpful metric but its 180 watts of LED.

 

So I have come to the conclusion that the primary problem with my system is too low light now that I have a PAR meter. PAR at the surface is only like 120 so I'm ramping up the LEDs over the course of a month. That said, I do still think there may be something to the sensitivity to certain wavelengths theory.

[BradVincent]

no, water is perfect because I tested everything and Its exactly where it should be (ca, mg, alk all perfect, nitrate and phosphate low but not undetectable, right where I want them).

Water quality is not your problem if you aren't making huge/rapid changes.

I keep SPS and LPS, primarily SPS. Tank is 75g display, wattage isnt a very helpful metric but its 180 watts of LED.

wattage is a much more helpful metric than not giving us any details at all. PAR would be better.

 

 

 

So I have come to the conclusion that the primary problem with my system is too low light now that I have a PAR meter. PAR at the surface is only like 120 so I'm ramping up the LEDs over the course of a month. That said, I do still think there may be something to the sensitivity to certain wavelengths theory.

120 PAR will not grow most Acropora and what people keep in SPS tanks very well. If that is what your tank is used to, then they will have issues if you quickly raise it too fast. I agree that they might be more sensitive to shorter wavelengths (UV, Violet, Royal Blue). This does not mean you should omit these, just that you need to raise light levels slower. My Acropora gets over 300 PAR (on the coral, not the water's surface) and I am questioning whether that is good long term, or I need more light.

[malawian]

oh I know thats not enough. My BC29 was making 420 midway through the column and thats what I want to see on this tank. Trying to find ways to get it up to that.