T5s and bleaching LPS - anyone noticed this?

[sphelps]

Originally Posted by Myka

Oh come on now Steve, there is no issue, it's a discussion - just an oddity that I was wondering if anyone else shared similar experiences, or had any ideas as to why this would happen. The T5s were the exact same bulbs (as stated above), removed from one fixture put into the new one. One Fiji Purple and one AquaScience 17,500K. However, I noticed bleaching with all the other T5s I had tried in the last 2 years as well (Giesemann and Hagen). I suppose they had different reflectors and different ballasts running them, so there may have been a bit of a change there, but I would think not much. They went from a Hagen fixture to a Degenbao fixture.

I was simply confused and was looking for clarity, I don't have a problem with the discussion which is why I'm participating. But it sounds like your problems are related to your previous lighting, if you always experienced problems with the T5 only setup, it's likely you didn't have sufficient lighting, especially if adding more intense lighting fixed the problem. Less than 80W is not very much light for any reef tank. It's not normal for T5s to bleach LPS corals, on average they will usually do better with T5 lighting over halides. Since my T5s stopped working in my fixture my LPS corals have not been looking too well, the halides still appear to produce enough light for the tank but it seems fairly obvious the T5s definitely add something the LPS corals like.

Also I'm still confused how your corals have been bleaching and have shown tissue loss for 2 years yet you still have them?? It also sounds like you've changed lighting many times which can also add to the problem you're observing.

I should also note that bleaching refers to the loss of color in a coral which is caused by death or loss of pigmentation of the zooxanthellae. Bleaching does not directly refer to tissue loss. Different lighting spectrums produce different results for coral coloration, sometimes giving the effect of bleaching. I've dealt with many people who experienced this, usually right after buying a new coral from a tank with different lighting. This is the only reason I mentioned it before.

[torrid_07]

hey, ive just started getting into corals, i have just purchased a zoo, and a kenyan tree (soft coral). now i have 8. 36w t5s in my 75 gal. is this too much light for my new corals? my lights are sitting about 6" off of the water is that fine or should i be lifting them? i have noticed that the coral almost lies down in the subtrate when the lights go off at night. is this normal? anyways any help with my new corals would be THE WORLD, thanks

[Doug]

Nothing is really to bright. Just proper acclimatization is needed.

All this to bright for certain corals now. Bah. In the mid to late ,90s I grew tons of various soft corals and lps corals under my 250w 65K Iwasaki. Not much brighter than those.

Just manage depth and/or lighting periods when changing bulbs or adding new corals, until they are use to the lights. The eggcrate with some window screen also works well for acclimatizing.

You can keep corals that require less light down on or near the bottom, with proper lighting, instead of trying to get everything up into the light.

[Myka]

Originally Posted by sphelps

I was simply confused and was looking for clarity, I don't have a problem with the discussion which is why I'm participating.

Sorry, your reply sounded like you were just trying to be difficult.

Originally Posted by sphelps

But it sounds like your problems are related to your previous lighting, if you always experienced problems with the T5 only setup, it's likely you didn't have sufficient lighting, especially if adding more intense lighting fixed the problem. Less than 80W is not very much light for any reef tank. It's not normal for T5s to bleach LPS corals, on average they will usually do better with T5 lighting over halides. Since my T5s stopped working in my fixture my LPS corals have not been looking too well, the halides still appear to produce enough light for the tank but it seems fairly obvious the T5s definitely add something the LPS corals like.

Moving the T5s further away from the LPS or moving the LPS further away from the T5s fixed the problem. I couldn't keep the previously named LPS anywhere near the T5s in my 16" deep tank. They all had to be on the sand. I just find this odd that the corals wanted to be 16" from the T5s whether a strong halide was added or not.

Originally Posted by sphelps

Also I'm still confused how your corals have been bleaching and have shown tissue loss for 2 years yet you still have them?? It also sounds like you've changed lighting many times which can also add to the problem you're observing.

On every T5 change out (every 8 months) I have changed spectrum, brand, and obviously PAR to try to find the perfect lamp combination. I went from a low Kelvin to a high Kelvin in an attempt to see if Kelvin would affect Valonia as the red spectrum increases algae growth, and it seemed like it may have had a fairly signifiicant impact interestingly enough. With every bulb change there were changes in the corals, as expected, but not once did I get bleaching from changing the bulbs out.

They have never shown any tissue loss, I didn't say anything about that. If a coral shows the beginning signs of bleaching I will do what I need to do to stop it. By no means have any of my corals been bleached for 2 years!! The worst of the bunch for bleaching is my open brain, it always had to be on the sand and off to the side of the 16" deep T5 tank where there was the least amount of light. Because that coral is quite nice looking I would try to slowly inch it out into the brighter light (I mean move it like 1" sideways every couple weeks or month, and it would start to bleach. When I changed out the 2x39w T5 fixture for the 2x250w halide w/ 2x39w T5 which was 8" off the water surface making the open brain about 24" from the lights the color actually improved. In fact, all the corals' colors improved. Now the open brain is directly under one of the 250w DE halides on the sand in the 24" deep tank, which is about 27" from the halides and T5s. It continues to look better and better every week.

So, I'm wondering what the simple answer to the bleaching is. Is it PAR? That doesn't make sense. Is it spectrum? Maybe. It is the T5s being too close? Maybe. I dunno, that's why I'm asking if anyone else has had similar issues.

Originally Posted by sphelps

Different lighting spectrums produce different results for coral coloration, sometimes giving the effect of bleaching. I've dealt with many people who experienced this, usually right after buying a new coral from a tank with different lighting. This is the only reason I mentioned it before.

Are you referring to how the spectrum changes the way to coral looks, or how the spectrum may change the actual color of the coral? Sometimes people are surprised when they buy a coral from a dealer who has it under 20K lighting, and put it in their tank which has 12K lighting, and wonder why it looks different. Well, that's not the case here, I'm referring to the coral itself has changed color. The color intensity has increased with the change in lighting. It just seems odd to me because I thought the open brain (for example) was bleaching because of too much PAR from being too close to the T5s since it would color up when it was moved away from the T5s, but now I am observing it under much greater PAR with an increase in color intensity.

The reaction is obviously not just a result of PAR, or at least not directly or singly. I'm leaning more towards spectrum, that maybe having a more complete color spectrum from the halides allows a much greater intensity to be used. That by using a bit of a broken spectrum using T5s (that's too harsh of a descriptor, but gets the point) makes the intensity of the T5 lighting seem greater to the corals. Just speculating here...

I'm wondering what the results would be if you placed coral frags in one tank where one side is lit by T5s, and the other lit by halide where the micromols of PAR were the same on each side, and the Kelvin rating was the same on each side what the effects would be. Try to limit the variables simply just to the "quality" of the spectrum. Maybe there would be little difference, maybe there would be significant differences. I wish I had the time, equipment, and money to try this out.

I know there was a similar experiment to the one I just described, but I do believe it just compared T5s of one brand to another if I remember correctly it may have been AquaScience VS Giesemann or AquaScience vs KZ. Anyone remember that??

Originally Posted by Doug

Nothing is really to bright. Just proper acclimatization is needed. All this to bright for certain corals now. Bah. In the mid to late ,90s I grew tons of various soft corals and lps corals under my 250w 65K Iwasaki. Not much brighter than those. Just manage depth and/or lighting periods when changing bulbs or adding new corals, until they are use to the lights. The eggcrate with some window screen also works well for acclimatizing. You can keep corals that require less light down on or near the bottom, with proper lighting, instead of trying to get everything up into the light.

I agree for the most part that nothing is really too bright, which is why I don't think this issue of bleaching was caused by PAR. It definitely wasn't caused by too fast acclimation either. I've always used length of photoperiod to manage acclimation to new bulbs, and I have never had a coral bleach from changing bulbs (well not in the last decade anyway, since I've been a bit wiser lol). I'm still wondering if it is in fact spectrum quality...good quality spectrum allows for more intensity...maybe??

[albert_dao]

Originally Posted by Myka

I know there was a similar experiment to the one I just described, but I do believe it just compared T5s of one brand to another if I remember correctly it may have been AquaScience VS Giesemann or AquaScience vs KZ. Anyone remember that??

It was ATI vs. AquaScience. I have the link at the office. I'll post it tomorrow.

[Myka]

Originally Posted by albert_dao

It was ATI vs. AquaScience. I have the link at the office. I'll post it tomorrow.

Awesome, thanks! I seem to remember the AquaScience kicked butt.