LED light spectrum for clams
- Thread starter A sea K
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I have read a lot in the past about clams requiring more white light than anything (or at least lower K light), but I never did find out any reasoning behind that and it seems people keep them just fine under blue heavy LEDs. I have noticed that under LEDs blue maximas turn more intense blue for whatever reason. I would think that very blue clams would need more blue light as they reflect that color, but I hope some clam lighting experts can say more.
I think it depends a lot on what species you are talking about. Deresa, squamosa and gigas are sand dwellers, often at decent depth, so a bluer light is OK. Maxima and Crocea live very close to the surface, so whiter is better. I never had better clam growth than when I ran 6500K bulbs in the late 1980s.
Good to know as I actually prefer a somewhat crisp/white appearance.
The clam is a Maxima, he's in a shallow tank near the surface so he is actually getting quite a bit of light I believe, with that said, due to the shallow nature of my tank the fixture is mounted higher than what most would, roughly 12" off the waters surface.
The clam is a Maxima, he's in a shallow tank near the surface so he is actually getting quite a bit of light I believe, with that said, due to the shallow nature of my tank the fixture is mounted higher than what most would, roughly 12" off the waters surface.
I still have never really heard an explanation of why lower K light was better for them except for the reason maxima and crocea are shallow so white is the way to go. I am not saying that is wrong, but I have never really heard why that is. I heard once they might have different zooxanthellae that respond better to white light, but I never have seen any more about that.
The forums used to say lower K was better for growing corals and 20k light would kill acros as they corals couldn't use actinic light. I have wondered if the white light and clam thing is a hold over from that era (early 2000's I think) or if there is really something to it.
Well, if they are found at very shallow depth, and evolutionarily adapted to a daylight spectrum, that would seem to be about the best explanation one is likely to get. Whether they can be adapted to a higher kelvin spectrum and kept long term is a different question. I've kept maxima under 14K light for years - but maybe they would have done even better under 10K.
I am not saying that's wrong, but that was the same thing many used to say about shallow acros way back in the day too and those folk thought actinic was totally useless as I said in the earlier post, until the hobby starting looking at the photosynthetic usable spectrum in more detail and saw green wasn't really used very well and after more experimentation that strong red really isn't ideal either, just the opposite of what one would think since shallow water has so much red in it.
If shallow clams act differently than shallow coral I would think there would some evidence that that have different zooxanthellae or some sort of different biochemistry taking place but I have not seen any sort of papers or anything saying that. Maybe I just missed them, but that is the type of evidence I was talking about but I didn't explain very well. I am not saying any of this to be contentious , I am legitimately curious if there are differences that have been studied.
Without getting into a conversation about how we define "better" (fast growth, coloring up - zooxanthellae density, growth forms) if for some reason I had to try keeping a coral reef tank under one of the three primary colors it would sure be blue over green or red. But thankfully it seems pretty unlikely that anyone would force me to do that!
Wazzel
New member
As long as it is getting full spectrum, I do not think it matters much if you get a blue spike like a radium or something else. I run a very white LED tank and my maxima is doing just fine.
As far as why people tend to blue tanks, well it became an arbitrary standard that got adapted over time for some reason. The actual spectrum that reefs get varies greatly. There is just not one way to keep the corals and clams happy.
As far as why people tend to blue tanks, well it became an arbitrary standard that got adapted over time for some reason. The actual spectrum that reefs get varies greatly. There is just not one way to keep the corals and clams happy.
There are many happy clams under high K value blue spectrum and still no evidence to my knowledge that would indicate more white light would be beneficial over just increased intensity across the spectrum or with just blues, but great to hear it's looking good! Hope it continues to do well for you!
Wazzel
New member
Just keep in mind that blue LEDs are narrow bands, unlike Mh and t-5 which are broad spectrum with a spike.
I never wanted to give the impression that I was pontificating the value of LEDs especially blue tanks. I don't like blue tanks over whiter tanks, nor feel they have any inherent value over other tanks or systems that has been clearly demonstrated. My only point was I have not seen any scientific evidence, or at least photosynthetic related evidence indicating that clams for whatever reason respond much better to a higher K light. There may be some out there, and I was hoping if there was someone would post a journal link if there was a large difference between coral and clams and light utilization for photosynthesis.
I wanted to suggest that idea may be a carry over from when the hobby wasn't very familiar with the photosynthetic spectrum and blue light was regarded as useless (in general). It may have come across that I was advocating use of blue LED over other sources, I am not, I just question the old clam "rule of thumb" that white is better for clams - there are enough examples of clams living under blue heavy light and white light that for captive systems they seem to do fine with either as long as the spectrum is reasonably complete.
I wanted to suggest that idea may be a carry over from when the hobby wasn't very familiar with the photosynthetic spectrum and blue light was regarded as useless (in general). It may have come across that I was advocating use of blue LED over other sources, I am not, I just question the old clam "rule of thumb" that white is better for clams - there are enough examples of clams living under blue heavy light and white light that for captive systems they seem to do fine with either as long as the spectrum is reasonably complete.
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