Can LEDs shift in spectrum?

[Bongo Shrimp]

I bought a custom LED fixture from nanotuners back when they were in business probably 4ish years ago. It has 15 white Cree XR-E stars and 15 blue. They were underpowered for a while because the drivers were not calibrated when it was assembled. Then evil66 helped me get them calibrated and they were much more powerful, sustaining SPS very very well. The success lasted for approximately a year, running the LEDs at 100% power using the ALC module with a Reefkeeper Elite and then things went haywire. I have been having trouble keeping almost any corals, especially SPS. My one mushroom is bleached, my zoas are somewhat bleached, and my darth maul porites which should be deep red, is pink. I also noticed that most if not all of my coraline algae has died or become extremely pale. I have tested the water over and over, checked for stray current and even heavy metals. My fish are fine and my numerous acro crabs and one pistol shrimp are alive and well along with my snails and two year old halloween hermit crab. I had given up.

Then today I noticed something. I noticed that the coraline that is slightly shadowed, aka not getting direct light, is pretty deep purple and seemingly healthy. It is very easy to see on the rear top corners of my tank and in some slightly shadowed areas on the rocks. Also, my porites is light pink on top but more red on the sides where it has grown down vertically on the rock I bought it on. So now I am convinced it has to be my lights. One friend of mine suggested the LEDs shifted in spectrum. I didn't think this was possible, nor does it make sense that some coraline would be healthy and the rest not because it only get less light, not a different spectrum (correct me if I'm wrong). Could I be running the LEDs too high? This is not a stability issue because I run a dosing pump which keeps my levels rock solid by dosing alk and cal 16 times a day. Mag is stable from water changes although I test it and adjust if necessary.

A few other weird symptoms include the SPS STNing slowly from the base for a few weeks, then going faster and faster, and eventually either stopping and getting better or just dying completely. Also I have been battling bryopsis which goes through a similar cycle of slowly dying off further and further and then coming back in force.

I hope this isn't too confusing, just trying to be thorough. LMK if anything needs clarification. I'm really at wits end and appreciate any input.

Tank stats:

Biocube 29g
15 White Cree XR-E LEDs and 15 Deep Blue @ 100% power via ALC with Reefkeeper Elite
Mediabasket in second chamber for filtration with polyfilter, carbon filter pad, chemipure and rowaphos
DIY Fuge with chaeto
2 Vortech mp10s

Temp- 78.5ºF
Salinity- 1.025
pH- 8.1 (API)
Alk- 9.8 (salifert)
Cal- 450 (salifert)
Mag- 1450 (salifert)
Phos- 0.03 (salifert)
Ammonia- 0 (API)
Nitrate- 0 (API)
Nitrite- 0 (API)

Tank inhabitants-
Pair of A. ocellaris
Pistol shrimp
A few hermits, a trochus snail and a few nerites

This is an example of what the LEDs were capable of several months ago:

I can get a picture of the difference in coraline coloration if anyone needs to see.

 

[usmc121581]

I am by no means an expert on LED's matter of fact I dont even like them. But it sounds like they are burning the corals and the coralline algea. I have also came across people who corals turned colors because of the wrong mixtures of colors in the LED lights.

I would try turning them down and not pushing them at 100%. Hopefully someone who has more expertise will chime in. Sorry cant be more helpful.

 

[asid61]

It's almost definitely not the lighting. If it was good years ago and worked, it should still be okay.
Leds do shift in spectrum, but it has little to do with age, and more to do with voltage. The shift is usually in the range of around 5nm, which isn't enough to hurt your corals. Running your leds at 100% probably didn't help the lifetime, but they should still be okay.
You could borrow a similar led fixture from a friend and see if that helps. If it doesn't, then it has to be the water or pests.

On a side note, those are some fantastic corals.

 

[Ron Reefman]

+1 for what asid61 said... which is very much like what I told you on another forum.

 

[alton]

As a rule LEDS drop 3% each year, some more, some less. That is why you don't run them at 100%. It is better to run them at 70% and raise them each year to keep everything happy. But this also requires a PAR meter. The eyes lie, if you can tell a shift, then it is too late for your corals and this rule is for MH and T5 also.

 

[Bongo Shrimp]

Thanks everyone for the replies and sorry for being so slow to respond. I have dropped the whites to 50% and blues to 75%. So now I'm going to give it a week or two and see if anything changes. I originally thought it had to be the water too but I have tested and tested everything over and over with different kits and different brand kits and its all reading fine. IMO it has to be the light because why else would there be such a stark difference in coraline growth and health right at the light line?