Bought Crocea but I only have PC lighting

[ejmeier]

Guys, I don't think this is a lack of light...

If there is insufficient light, wouldn't there be mantle overextension? It would make sense that a clam would do this in an attempt to get more light. Also, there is usually a slow decline including bleaching when a clam has a lack of light.

I am guessing that this clam "shut-up" instance is from a water quality issue if anything. I mean, if you look in Knop's book, pratically every cause of a clam not fully extending its mantle is due to a water quality or parasitic problem. Crocea's are also known to be the most sensitive as well.

No offence intended to jimmerpro, but the fact that he made an impulse buy may indicate he is simply not ready for such an organism - even if he were to upgrade to MH lighting. (Don't kick yourself though, I used to make impulse buys ALL the time...)

jimmerpro - I would recommend following this link and reading ALL the articles here:http://www.reefs.org/library/aquarium_frontiers/On_The_Half_Shell.html this is a wealth of information concerning clams, and information is power.

 

[Mad Scientist]

My guess would also be water quality issues, probably low Ca and alk.

 

[DarkDevil]

my clam is still kicking, just one of the clam died under PC doesn't really mean it "must be" the lighting condition, jumping to conclusion like that doesn't make sense at all, it could be the clam is already dying when he bought it, there may be predator, there may be water condition, who knows, just please don't keep telling ppl PC light will NEVER work, I always tell ppl, nothing is impossible, if you don't learn the main reason, everything will be impossible, go check out nano-reef.com, many ppl actually have SPS + clam under PC lighting, and many have survived, I still stand my point, it MAY NOT be the light, it could be anything

 

[brianlena2000]

If there is insufficient light, wouldn't there be mantle overextension?

Not necessarily. Most clams will close up (not completely of course) at night when the lights go off. If you run a dusk/dawn schedule you will notice that they open a little more for the actinics only lighting then fully open up when the main lighting comes on (provided that the light is sufficient).

While this could very well be a symptom of a disease/predator it could also be the lighting.

 

[brianlena2000]

go check out nano-reef.com, many ppl actually have SPS + clam under PC

Sorry, but that comparison doesn't work for two reasons. First of all those tanks are much smaller and the lighting doesn't have to penetrate through much water (PC's lose their intensity much faster than halides as they penetrate through water). Also, many of the clams being kept in nanos are still at a size where they rely on feedings more than light. This crocea is 4" and therefore will rely primarily on lighting to meet its needs.

 

[ClamLover]

Picture yourself snorkelling/swimming at five feet depth in a tropical reef, Tridacna Croceas and Maximas below you, staghorns and tables everywhere, almost like paradise or maybe it is.

Stop! Take a look upwards vertically towards to the sky (or sun) above you, your eye lids probably can't open up at this stage.

That is the kind of intensity you need for Croceas/Maximas.

Go forward to maybe further 20-30 feet depth, there you see the Squamosa or other larger species variants. The water under you probably doesn't look that bright as at 5 feet depth...

 

[ejmeier]

I remember back when I had PCs, I used to resent the people that always said "MH only" as if in some sort of exclusive club.

Now, I use pretty much nothing but metal halides, and I love them. I always try to steer people towards metal halides for most reef setups. I am clearly an advocate for MHs and keep my clams under a 400w MH.

But, I STILL resent those who are always saying "MH only." While it's true that for an all-out "clam-tank" you would most certainly want a MH setup - mainly for the practicality of putting a clam basically anywhere you wish - I don't think it is an absolute necessity for only ONE clam. That is to say, if you have one clam in a PC or VHO lit tank, you need him in one spot - at the very top - so space is limited.

Is there something magical about MHs?

True, they pierce through the water deeper. But at under one foot of depth, you would hardly be able to notice the difference between a 175w MH and a strong PC setup. Both ARE capable of delivering substantial amounts of PAR to the organisms directly below the light, but PCs and VHOs are somewhat limited in that they cannot penetrate to enough depth to be practical to those wanting a "clam" or "SPS" tank.

I believe jimmerpro did say that he had his clam located on some sort of LR "shelf", and while he didn't give the exact distance from the light, if it is within a short enough distance from his PCs, the clam will receive enough light to not only sustain itself, but thrive.

IMO, it is all about intensity, and if something is close enough to the lights, even 96w PCs can do the job, albeit in a somewhat impractical way.

 

[lebowski]

IMO, it is all about intensity, and if something is close enough to the lights, even 96w PCs can do the job, albeit in a somewhat impractical way.

Put something half as close to the lights under MH as opposed to PC and see the difference... Having a crocea under PC's CAN WORK!! But in this persons case, the PC setup he has is simply VERY weak...

 

[tim n heather]

I have just gotten a reef tank, 85 gallon. and although I know I don't need to get a clam for 6 months to a year, i want to make sure i can get one when time is right. I need to get lights for my new used tank. I get I should get MH, but how much wattage should I get for a 85g