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Warning To All Potential Clam Owners!

6K views 21 replies 15 participants last post by  shred5 
#1 · (Edited by Moderator)
Eventhough you may have metal halides HID lamps, 20000K does not provide enough PAR for the clams! Even if you put clams near the surface of your tank! Crocea and Maxima are grow in shallow waters!

Here's my experience. I had 7 croceas and 4 maximas in my 8ft tank for two and a half years... using 3x10000K Ushio Aqualite metal halides. All supercoloured, super rare collection. Then one day I saw a tank (friend) using 20000K lamps, which has a blueish colour, I thought... wow, that was so beautiful compared to my yellowish-greenish tank even without blue actnics. So I switched all 3 bulbs.
Within the first week, everything seemed normal! Then in the second week, all clams died simultaneously within 2 days, leaving only one alive-located at the corner of tank closest to window(sunlight)! ALL OTHER CORALS ARE DOING GREAT! Only clams died. I had no explanation! Gave up clams for a year plus.

Then, I setup a new tank, thinking that the cause of clam wipeout in my previous tank was a disease outbreak. This time, I tried 2-3 croceas until I gave up. BTW, using 20000K. And I said, I did not have a problem when using 10000K, and I tried reluctantly due to the unattractive color. Now having 7 clams for 8 months already.

So, please spread the word. Clam tanks NEED 10000K lighting! Learn from my stupid mistake.
 
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#2 · (Edited by Moderator)
Eventhough you may have metal halides HID lamps, 20000K does not provide enough PAR for the clams! Even if you put clams near the surface of your tank! Crocea and Maxima are grow in shallow waters!

Here's my experience. I had 7 croceas and 4 maximas in my 8ft tank for two and a half years... using 3x10000K Ushio Aqualite metal halides. All supercoloured, super rare collection. Then one day I saw a tank (friend) using 20000K lamps, which has a blueish colour, I thought... wow, that was so beautiful compared to my yellowish-greenish tank even without blue actnics. So I switched all 3 bulbs.
Within the first week, everything seemed normal! Then in the second week, all clams died simultaneously within 2 days, leaving only one alive-located at the corner of tank closest to window(sunlight)! ALL OTHER CORALS ARE DOING GREAT! Only clams died. I had no explanation! Gave up clams for a year plus.

Then, I setup a new tank, thinking that the cause of clam wipeout in my previous tank was a disease outbreak. This time, I tried 2-3 croceas until I gave up. BTW, using 20000K. And I said, I did not have a problem when using 10000K, and I tried reluctantly due to the unattractive color. Now having 7 clams for 8 months already.

So, please spread the word. Clam tanks NEED 10000K lighting! Learn from my stupid mistake.
 
#4 ·
What wattage bulbs were you using? What brand of bulbs and ballasts?

Sudden death of a specific inhabitant generally points to a parasite. Were there any additions (fish, coral, clams, live rock, etc.) within those 2 weeks?


I'm running 175W 15000k bulbs on a 30" tank with clams on the bottom -- 3 months and a 1/4" of growth on the maximas. It's all about the PAR output, not necessarily the color temperature.
 
#5 ·
I agree, I've talked to the Ushio guy at the last aquarium show and he said the PAR value of a 20k is about 1/3 of the 10k. That was testing the bulb on a table; I would think the difference after a few feet of water would be even greater. It could also be the extreme change in PAR not necessary the par value itself because I’ve known more then one person with clams under less lighting then that without issues.
 
#6 ·
Changing your lighting will not cause the clams to die withing 2 days. There was something else going on there (agree with Vince on possible parasite).

While yes, the PAR output from a 20K is far less than a 10K, it also depends alot on how much wattage and your equipment choices are as far as relating to ballasts and reflectors. Parabolic reflectors are far more efficient at getting the light down from the bulb and into the tank than older style spider reflectors and such. For instance, I use 14K Phoenix bulbs over my system and using 150's with high end reflectors compared to a 250w Icecap reflector, the 150's are as bright or brighter comparably.
 
#7 ·
I keep a maxima under 6 T5's in a 125g on the sandbed...4 bulbs are blue plus and 2 are daylight so much like a 20k in color...he has been happy under that lighting for over a year...I would tend to agree, something more than lighting must have had an effect on those clams.
 
#8 ·
I agree with everyone else. While it's terrible that you've lost your clams, you've nowhere near the proper proof to declare that clams need 10kK lighting. On the contrary, I'd say there's overwhelming evidence that lighting temperature is only one small facet of what clams need, and I've run mine under 14kK, 10kK, and 20kK without any issue. Not to mention the sweeping temperature ranges from the T5 bulbs I've used.

If you're really concerned about what happened to these clams, I'd do a LOT more investigating before determining bulb color temperature was your issue. Did you even measure PAR between the setups? If you had old 10kK bulbs, the 20kK may have even put out MORE light than your old bulbs.
 
#10 ·
I have to disagree.. Even though I never have kept them under 20k lamps because I think they are ugly I know a lot of people who have.

So basically what you are saying is if I had 150 watts of 10k lighting I would have more par than 400 watts of 20,000? Think about what you are saying here?
 
#11 ·
Good point. Yes a 400W 20000K would have more PAR than a 150W 10000K. Sorry forgot to mention that I am having a 2ft deep tank with 250W 10000K.

This is what I tried and worked (talking about a single lamp and clam directly under it): [Just my experience and estimation, talking about supercolored maxima and crocea, of course those with brown and less blue mantles are more tolerant)

10000K 150W, clams can be put up to 1.5ft depth.
10000K 250W, can be up to 2.5ft depth.
10000K 400W, can be up to 4ft depth.

20000K 150W, clams ---I couldn't do with supercolored ones at any depth.
20000K 250W, can be up to 1ft depth.
20000K 400W, can be up to 2ft depth.
(non radium, note that the radium bulbs might have better results).

14000K ones, I never tried them. I am guessing that it should be in between 10000K and 20000K results? But keep in mind that the PAR (for red and yellow wavelengths) is reduced a lot after 10000K, also depending on the ballast and bulb brands. Ushio Aqualite has it quite balanced throughout wavelengths, but other brands might show high peaks on yellow and green, but very low in between those wavelengths.

For 20000K 150W, I am not saying that it will kill the clams within a week or two. Mine died because (I assume) that they are so used to 10000K and when I switched, the food supply from the zooxanthelae is significantly reduced to less than half. Hence wiped out within less than two weeks.

For a new clam (supercolored), I put it in a 20000K 150W tank at less than 1ft. It lasted somewhat more than month, then also died. From my experience, clams do not show any signs of bleaching and starvation, just shrunk and died within a day or two. I am guessing that either the wavelengths (PAR) does not satisfy the clam, or it might be 'burnt' because it was too close to the water surface. However, the ones and 1.5ft with the same bulb died within less than 2-3 weeks.

Sorry for not clarifying, however I can say that if you use 10000K lamps, the chances of a clam dying (due to lighting) is much less at any depth.

If we start comparing between brands and ballast it would no longer be a general assumption as in this thread. As I said, I am just giving estimated results based on what I have practically tried.

But you can compare and see detailed results here: http://www.manhattanreefs.com/lighting
 
#12 ·
"Super-colored" is a marketing term. There is no physiological difference in their lighting requirements. They are all collected around the same general depth (per species). ;)

PAR is the primary concern when it comes to lighting corals and clams. I'm running a 30" tank with 175W 15Ks. Been up and running for three months, with good clam growth at the bottom.

Thank you for clarifying that this is anecdotal and a general assumption. Blanket statements are a little to prevalent in the hobby. :)
 
#13 ·
I too disagree I keep clams under 150w 20k bulbs in about 18inch of water with no problems what so ever actually have awesome growth I think there are other issues here besides clams needing 10k bulbs it is possible that you shocked the clams by changing color temps over night
 
#15 ·
I'm a firm believer that great water quality is more important than massive lighting power. My tank is modestly lit with 2x 150w HQI (10000K and 14000K) and 4x 54w T5HO (420NM,420NM,460NM, 10000K). My clams are perfectly happy, mantle extension and color has only improved since they were purchased.

If your clams died from malnutrition caused by a decrease in par, wouldn't they have bleached first? I've seen croceas survive under two T5NO strips for extended periods of time (6+ months), They lost most of their color, but seemed otherwise healthy.
 
#16 ·
Ok I was hoping for a reply. My case was a little extreme I know but it was meant to be. But yes lamps usually put out less par as Kelvin rating goes up.

You do not always see this when testing individual lamps because some lamps are just better than others. Good Reflectors and good ballast make a huge difference too. So just saying a 10,000 k lamp can keep clams and 20,00k can not is just not true. A good 20,000k setup will beat a average 10,000k setup.

But of coarse if you have a setup putting out less par your calms will have to be kept closer to the light source. But a 250 watt 20,000 can keep clams just fine, they will just have to be closer to the light.

Also Neuticle mantel extension is not always a reaction to good lighting, it can be to decreased lighting. They can be extending the mantel to get get more light. Corals do this too, they will expand to get more light and contract to get less light. Neuticle those 4 t-5 you have are probably putting out more par than those 150's if they have good reflectors and lamps so depending on your tank size you could have allot of light.

Bcrum51
Croceas and maximas require higher light than deresa. Keeping clams in 18" of water under 150w is pushing it a little. Deresa I have kept just fine under n/o fluorescent but would never suggest anyone do this.

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Another thing, people saying you have such and such a light with out telling your tank size means nothing. 150w over a 10 gallon can be allot of light but a 150w over 100 gallon would have a hard time growing a mushroom.

Also bleaching usually happens under an increased lighting, this is because now the zooxanthellae go into over drive due to the higher lighting. They start producing more oxygen and food sometimes more than the coral can handle and the get rid of the zooxanthellae.

Corals and clams usually darken under less lighting or brown out. This happens due to increasing in the amount of zooxanthellae so the clam or coral can get more food due to the zooxanthellae producing less food. There is a point though where they will look like they have bleached if there is not enough light for the zooxanthellae and they die all together.

Pigments and proteins that cause some of the pretty colors in corals and clams are a different story altogether. Corals can shift or change them either to shade or gather more light.

This last section is kind of a generalization because there are so many theories and other factors that can come into play but I made it simple so people can understand it.
 
#19 ·


Bcrum51
Croceas and maximas require higher light than deresa. Keeping clams in 18" of water under 150w is pushing it a little. Deresa I have kept just fine under n/o fluorescent but would never suggest anyone do this.

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What makes u assume I'm keeping deresa clams I have one deresa and one crocea both of which are very healthy both on the sand bed
 
#17 ·
I would also have to disagree.

I'm a firm believer that great water quality is more important than massive lighting power
I tend to agree with this statement that was posted above. Also, most people do not consider tank mates and some will stress the clam so it will not open as much and you can guess what the end results are.

No doubt that the more intense lighting you have the better but with that being said, I know of a person here that has clams under T-5 and has been there for over a year and the clams look great!
 
#18 ·
FWIW, I just sold my squamosa clam that grew from 3 1/2" to 18", too big for the tank, and, I still have a purple crocea that has gone from 3" to about 6" now.
My tanks, including this one, are all lit with 40 NO fluorescent lamps.
The crocea may not look as nice as under MH but the squamosa is every bit as good as any I ever saw under any lighting.
The point is, that you don't need MH to keep them alive so I doubt that the K rating will be a determining factor in life or death.
IMO, K rating will only make the clams appear different than they do under different lighting.
 
#21 ·
As with everything in this hobby, no two setups are the same...while there is some obvious success under "lower" lighting, I think we can all agree that Crocea and Maxima clams are best classified as "high light" animals...that said, just like all the other light loving animals we keep, lighting is only one piece of the puzzle...there are many other factors that need to be weighed if one is to successfully keep clams.

I will add that I too have to disagree that 20K bulbs are unacceptable for high light clams...I run 6x T5's with a bulb config that is very much like a 20K on a 125g tank with a Maxima on the sand bed...in a year or so the clam has easily gone from 3" to 6"+...but again, I attribute much of that to other husbandry factors, not just adequate lighting.
 
#22 ·
Bcrum51
Where does it say I assumed you had a deresa? I used as ann example of something I kept.

Jnicho..HO T-5 lighting with good reflectors will keep up and in allot of instances put out more par than halides. Just because it is fluorescent technology does not mean it is weak. Halides have a hot spot where there will be high par but average par is better with t-5. People underestimate t-5 lighting and that was why so many people had corals bleach when they switched to t-5.
 
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