Lighting Requirements for Tridacnids
- Thread starter ezcompany
- Start date
hahnmeister
In Memoriam
Clams arent as picky as some people make them out to be.
The rule of thumb was always "needs lots of light" because they are usually kept in tanks with halides, yes. But often, they are on the sand anyways, and years ago when that standpoint was developed, sure, it took alot of watts to get the light needed.
Now we have better reflectors, more efficient bulbs (and in many bluer colors), and better ballasts. Yet we still think they need alot.
Okay, so I have been doing PAR readings of clams for a while now in fellow reefers tanks. I found that a vast majority of maximas and croceas are in only 100-130 MicroMol/m2/s intensity light, and doing awesome.
Can they take more? Of course. But do they need it?... no. Sure, they were kept in tanks with high-intensity, but that doesnt mean they are kept themselves in that high intensity light. They are often in the sand. Considering how crappy reflectors were 6-10 years ago in this hobby, I would imagine it would take alot of light to get that 100-130 down on the sand. Now though... its easy. T5s can easily do that.
The rule of thumb was always "needs lots of light" because they are usually kept in tanks with halides, yes. But often, they are on the sand anyways, and years ago when that standpoint was developed, sure, it took alot of watts to get the light needed.
Now we have better reflectors, more efficient bulbs (and in many bluer colors), and better ballasts. Yet we still think they need alot.
Okay, so I have been doing PAR readings of clams for a while now in fellow reefers tanks. I found that a vast majority of maximas and croceas are in only 100-130 MicroMol/m2/s intensity light, and doing awesome.
Can they take more? Of course. But do they need it?... no. Sure, they were kept in tanks with high-intensity, but that doesnt mean they are kept themselves in that high intensity light. They are often in the sand. Considering how crappy reflectors were 6-10 years ago in this hobby, I would imagine it would take alot of light to get that 100-130 down on the sand. Now though... its easy. T5s can easily do that.
Back to PAR, these values are most important as they represent the "useable light"; however, not all organisms, and clams in particular, utilize the same PAR. This is due to the fact that their are many subtypes of zooxanthellae resulting in different light absorbtion spectra. Contrary to what would be thought, coloration (such as mantle color) has little to do with light spectra absorbed, as these only represent fluorescent proteins that have no part in photosynthesis. As I have found in my experiences and those of others, clams are unique, individual organisms that can be usually found within certain ranges of the reef habitat, yet that doesn't mean that's where they do best. Where clams are found in nature represents an area of toleration (within a wide range of growth) as far as lighting, nutrients, and current are concerned, but most importantly represents an area of low predation and hydrodynamic impact. To determine "YOUR" clams best closed habitat, one should experiment with position and types of lighting.
Additionally, water purity and ionic stability is of vital importance to clam health. Even micro-levels of certain heavy metals (cadmium, copper, etc.) are strong "poisons" of cellular mitochondria in bivalves. This results is deceased aerobic efficiency and drastically compromised immune responses, making the clam susceptible to disease (perhaps involved in pinched mantle???). I would recommend only the use of RO/DI when keeping clams of any species, or genus for that matter. Secondly, I have found that ionic stability (particularly of Ca/Alk) are key to shell deposition and mantle expansion. The majority of clam systems that I have troubleshooted are growing poorly due to imbalance.
hahnmeister
In Memoriam
What you say is very true for corals, but clams will pretty much adapt to whatever spectrum you throw at them.
Fedcopmike
In Memoriam
One question not answered is for how long should the halides be on daily over the clams? Regular Flourescents are on 12 hrs.
ezcompany
Premium Member
the sun rises, stays, and falls for 12 hours in the equator of earth. if you want to replicate the exact amount of light they receive in tropical reefs near the equator 10-11 hours is around the norm. clams do exist in places much further from the equator also, such as the red sea and great barrier reef. they would probably shave of an hour or two of light. in our systems, i would say 10 hours is safe, with 9 hours being no danger as well.
whatsamatanow
New member
I have built my own LED lamp using shell from old flouresent fixture and a transformer from local electronics store. Took lot of research (esoterics abound).Very happy with results and so are my little buddies.
gulfstream
New member
clams
clams
Since this has come on the open,I've been having discussions with other mambers here in my city regarding Clams>>....
so the question is........would clams do ok with T5 lights,which seems to be a new trend going!!
I keep mine under dual 250w bulbs......but I would like to get
my doubts out.
thanks
clams
Since this has come on the open,I've been having discussions with other mambers here in my city regarding Clams>>....
so the question is........would clams do ok with T5 lights,which seems to be a new trend going!!
I keep mine under dual 250w bulbs......but I would like to get
my doubts out.
thanks
hahnmeister
In Memoriam
Clams will do fine under T5s. In fact, I would bet they will get more light if at the bottom of a T5 lit tank than a halide lit tank of similar wattage.
Like I mentioned before, the perception of clams that need alot of light was developed years ago when lighting options werent very efficient. The only alternative to halide was a PC system... and PC systems suck at getting the required amount of light into the tank, you know? The sand in most PC lit reefs is lucky to be under 30-50 micromol's of PAR. With halides back then, getting 100 to the sand was good, and this would be sort of the minimum for croceas and maximas. This is where the perception came from.
Now, lighting systems can easily make light values in the 200's at the sand with the same wattage, even more so with T5s because they penetrate the water better. This is plenty for clams.
Oh, BTW, I would say a 8-10 hour photoperiod is ideal. I go 8 hours of halide+T5, with a one hour before and after of just T5s. I have gone as little as 8 hours with the T5s though (all on, all off) and been just fine. In nature, sure, the daily photoperiod might be about 11 hours, but much of that is 'off peak' like in the morning and late afternoon. During the noon peak, the intensities might be much higher than what we have in our tanks, but this is only for a couple hours, if that. For much of the day, our tanks tend to provide more than what they are getting in nature otherwise, and because of this, having a 10-12 hour photoperiod doesnt make the best of sense (unless you have very weak lighting you are making up for).
Like I mentioned before, the perception of clams that need alot of light was developed years ago when lighting options werent very efficient. The only alternative to halide was a PC system... and PC systems suck at getting the required amount of light into the tank, you know? The sand in most PC lit reefs is lucky to be under 30-50 micromol's of PAR. With halides back then, getting 100 to the sand was good, and this would be sort of the minimum for croceas and maximas. This is where the perception came from.
Now, lighting systems can easily make light values in the 200's at the sand with the same wattage, even more so with T5s because they penetrate the water better. This is plenty for clams.
Oh, BTW, I would say a 8-10 hour photoperiod is ideal. I go 8 hours of halide+T5, with a one hour before and after of just T5s. I have gone as little as 8 hours with the T5s though (all on, all off) and been just fine. In nature, sure, the daily photoperiod might be about 11 hours, but much of that is 'off peak' like in the morning and late afternoon. During the noon peak, the intensities might be much higher than what we have in our tanks, but this is only for a couple hours, if that. For much of the day, our tanks tend to provide more than what they are getting in nature otherwise, and because of this, having a 10-12 hour photoperiod doesnt make the best of sense (unless you have very weak lighting you are making up for).
gulfstream
New member
thanks
thanks
thanks .....
for a very useful info....
I got 3 clams (wife addiction)LOL
I got a dersa/Squamosa and a bright red which I don't know what type it is.however I find them to be doing very well with the MH and tend to retract a bit once the t5 come on.
other than that they seem fine.......
as for your info I will pass your info to other people who have same doubts I did.
thanks.
thanks
thanks .....
for a very useful info....
I got 3 clams (wife addiction)LOL
I got a dersa/Squamosa and a bright red which I don't know what type it is.however I find them to be doing very well with the MH and tend to retract a bit once the t5 come on.
other than that they seem fine.......
as for your info I will pass your info to other people who have same doubts I did.
thanks.
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