Clams and Lighting

[fishhead]

I've heard interesting comments on clams and their lighting. I just got these 2 guys about a week ago and they are they under a 250W XM 20,000K Halide with a 4' actinic blue(420nm) VHO and a 4' "50\50 super saylight" VHO. Do you folks suspect they will suffer due to my recent change (about amonth ago) from the OSHIU 10K to the XM 20K?

[addict]

It has less to do with spectrum than it has to do with intensity.
Watt-for-watt, 20K bulbs have less output than bulbs lower in the spectrum (10K, 6500K).
When I upgraded to 20K bulbs waaay back, I went from Ushio 250w 10K's to Ushio 400w 20K's to get around the same intensity.

Now as for your question, it depends. (I bet you love that answer).
Everything is pretty much dependent on how high your lights are over your tank, and how deep your tank is. With 250w bulbs, you pretty much want to keep the clams between 18-24" below the light... any more than that and they may not do as well. With 20K bulbs you probably want to stay closer to 18" than to 24".

Of course there's exceptions to every rule too... some people are having great success with just running T5's and no halide lamps.

One other thing is that baby clams need to be target fed a lot of phytoplankton until they're over 2" to 2-1/2" big, because they don't have enough zooxanthellae to feed themselves with light. I usually just stick them in a bowl of saltwater and add a few CC's of DT's and remove them once they've cleared the water... usually about a half-hour or so. Crocea's are also the most light-loving of the clams, and need more light than the rest of the clam species.

[fishhead]

Grrrrrrrrr. Thanks.

[fishhead]

Originally Posted by addict

It has less to do with spectrum than it has to do with intensity.
Watt-for-watt, 20K bulbs have less output than bulbs lower in the spectrum (10K, 6500K).
When I upgraded to 20K bulbs waaay back, I went from Ushio 250w 10K's to Ushio 400w 20K's to get around the same intensity.

Now as for your question, it depends. (I bet you love that answer).
Everything is pretty much dependent on how high your lights are over your tank, and how deep your tank is. With 250w bulbs, you pretty much want to keep the clams between 18-24" below the light... any more than that and they may not do as well. With 20K bulbs you probably want to stay closer to 18" than to 24".

Of course there's exceptions to every rule too... some people are having great success with just running T5's and no halide lamps.

One other thing is that baby clams need to be target fed a lot of phytoplankton until they're over 2" to 2-1/2" big, because they don't have enough zooxanthellae to feed themselves with light. I usually just stick them in a bowl of saltwater and add a few CC's of DT's and remove them once they've cleared the water... usually about a half-hour or so. Crocea's are also the most light-loving of the clams, and need more light than the rest of the clam species.

Thanks so much for the tips!! I didn't want to disturb the little clam, so I put a cup OVER IT WITH A HOLE ON TOP AND FED IT ALL i HAD AT THE TIME.."PHYTOPLAN" by two little fishes and some selcon. I don't think it ever would have cleared selcon out, so i removed bowl after about 15 min. I shall get some DT's at my LFS tomorrow and use that...excellent advice. thanks again ,
\ Greg

[fishhead]

Oh ya, I also moved the big crocea directly under the 20k and as close to the 50/50 VHO..it is a bit brighter there. He sits on sand bed 27" from the light bulb proper and 19" below water surface

[fishhead]

Also, I went to adjust the little guy a bit to give him that angle with valve pointing more or less upward, but he would not budge. Hmm. The little one seems to have put his foot down and wants to stay, whereas the large crocea just lifted up and accepted his new home(he did have a little sand stuck to his foot, but anchored like small one at all).

[fishhead]

Is frozen Cyclopeze too course for clams?

[addict]

Cyclop-eeze is zooplankton, not phytoplankton (it's animal, not vegetable).

DT's is a good source, unless you have access to other brands. Live phyto is best, though I've never tried the 'dead' stuff for clams... always DT's.

It's pretty difficult to do it in the tank without a lot of it washing away (even covered), so you should get it out if at all possible. I usually just put the bowl in the tank, set the clam in it, then lifted the bowl out of the tank (after emptying a bit of the water so it wouldn't spill), then set it on the counter and added the DT's until the water was a murky green. Clams are great phyto filters, and they would clear the water (mostly) in about a half-hour, then I just reversed the procedure to put it back in the tank. That way it's never out of the water and it greatly reduces stress on the clam.

If it's foot is attached, you can clear the sand around it so that you have access and gently pull the foot/byssal threads off the glass bottom. Since it's only been there a week there's probably only a couple of threads attached and it shouldn't be too detailed of a procedure.

It sounds like you're doing well on everything else.

Good luck.

[chris&barb]

Originally Posted by addict

If it's foot is attached, you can clear the sand around it so that you have access and gently pull the foot/byssal threads off the glass bottom.

never pull on a clam to detach it. you can rip the threads from the gland and cause an infection. just tip it to one side an cut the threads as far away from the clam as you can.

just to add, clams mantles are fully developed and full of zoox at a very early age(about a month) so the old saying that clams cant support them selves with out filter feeding untill 2 or 3" is not true. that was started a few years back when someone wrote an article FOR a phytoplankton Co. to sell phyto. heres a study where young clams were kept in micro filtered water, and never received any type of particulate and they did just fine on light alone.

http://links.jstor.org/sici?sici=000...2-N&size=LARGE

[fishhead]

I could not find DT's around here, so I go something by Kent Marine called Phytoplex. Do you feed your clam daily? weekly?
Thanks, Greg

[lcstorc]

I am aboout 75% through a great clam book. "Giant Clams of the Sea and the Aquarium" Lots of scientific references and seems to be a guy who knows what he is doing.
First off get that Crocea on some rock. They are rock dwelling clams and are much happier there. Many people have them attach to a small flat rock which they then move to where they want it. In the wild both crocea and maxima will actually eat through the rock and end up in a hole with only the mantle showing.
Also these are the clams taken from the shallowest water and thus need more light than say Gigas who are found in deeper water.
Finally and most importantly clams can get all of the energy plus a lot of extra from the light feeding the xanthella. They will filter feed but they do not need it once they are a couple of centimeters. I forget the formula and am too lazy to get the book right now.
It is however a great book loaded with info and incredible pictured.

[fishhead]

Thanks. Gave 'em some DT's I found anyway, and went back to 10000K from 20kK, and put'em up on the rocks. Much better. Thanks

[fishhead]

Originally Posted by fishhead

Thanks so much for the tips!! I didn't want to disturb the little clam, so I put a cup OVER IT WITH A HOLE ON TOP AND FED IT ALL i HAD AT THE TIME.."PHYTOPLAN" by two little fishes and some selcon. I don't think it ever would have cleared selcon out, so i removed bowl after about 15 min. I shall get some DT's at my LFS tomorrow and use that...excellent advice. thanks again ,
\ Greg

OK, went back to 10kK MH and got clams on rock about 5" from surface

[lcstorc]

You should check out the book "Giant Clams of the Aquariun and the Sea" It is a great book with lots of info on Triacnids and their care.

[burning2nd]

my clam is singing "Blinded by the light, something something something in the middle of the night"

70watts of HQI (14k) to a 5 and half gallon

so food is not reqired but i do give a little Cyclop-eeze (red powder) from time to fime just to make them all happy and see the hermits go nuts,