Out of the frying pan, into the fire...help! (Giant Clam related)


New member
Good news: I started calcium additions and my green and red algae went away :)

Bad news: A well meaning client gave me a giant clam for my tank. About 4 inches long, medium brown with gold spots and a green rim around the lips. The shell has little 'scallops' protruding and the mouth openings have little frilly bits, so I ****think**** it's a Tridacna maxima, but I'm not positive...

(1) How do I determine what it is?

(2) How in bloody blue blazes do I keep it happy?

Tank specs:

29 bow front reef
2x55 watt power compacts (10k 50/50)
1x15 watt actinic normal output flourescent
skimmer, power head for movement, Magnum HOT (running 50/50 mix carbon and biobeads)

pH 8.0
Temp 82
Ammonia, Nitrites, Nitrates: 0,0,0
dKH 7
ca 300 (before I started Ca additions, will check tomorrow)
Phosphates 0.2

Tank mates:

1 6-line wrasse
3 firefish
1 bi-colour blenny
3 camel shrimp
1 anemone crab (with bulbtip anemone)
6 algae snails
5 red leg hermits (hitchhikers on live rock)
1 blue leg hermit (ditto)
a few soft corals (leather, mushroom)

tank has been set up since june 1.


I'm an American, and I remember
Staff member
RC Mod
I'd be happy to move this thread for 'ya,
I think you're gonna need more light, but let's let the experts on clam care make that call.



New member
So it's a squamosa?

So it's a squamosa?

and not a maxima? How do you tell the difference?

And in reply to the lighting question...do I need to go to metal halide, or just more wattage in power compacts?


Premium Member
Honestly, I would see if you can find someone to take care of the clam for you while you make changes to accomodate him IF you decide you want to keep clams. I am not one who believes that all clams require MH but if you don't have MH you need a boatload of flourescent (PC or VHO) lighting. I have a 38G with 380W of VHO lighting for small clams that I feed directly. I am setting up a 72G w/ MH's for the clams when they get bigger and for new clams.

You have several small problems that the clam won't like besides lighting. None of them are catastrophic in my opinion but the cummulative affect probably would be. As you already know, your Ca and Alk are too low. I try for Ca 400-450 and Alk 9-12. PH should be 8-8.2 so you are good there as long as it's stable. The other things that would make me nervous are the camel shrimp, which have a habit of snacking on fleshy corals or clams, and the hermits which are just hit or miss and not worth the risk in my opinion.

Like I said, I would try to find someone to take care of the clam until you get your chemistry issues resolved. I'm not sure the clam wants to go through the raising of Ca and Alk with you. I think those two parameters along with the lighting and camel shrimp are the biggest hurdles you have. I think clams are worth the accomodations they require. I love 'em. My new tank will have only clam maintenence fish, a few nice corals and a bunch of clams. Good luck with the clam. I hope you are both successful. (you and the clam) :beer:

BTW: These are just my opinions, I have done a LOT of research but my actual experience is limited. It will stay limited regarding crabs and camel shrimp because I won't ever keep them with my clams! Again, Good luck! :D