Crocea darkening, losing intense coloration

[10" Red Devil]

Hello,

I have about a 3.5" Crocea clam, for about 3 months now. Unfortunately I had an accident a while back with a heater and it fried most everything in my tank except for this guy. It did bleach out, but alas it has finally regained it original color. Now before this incident it was starting to darken overall, it lost alot of its brilliant turqois color. Now that i has regain its xoa it has gone back to this darker color.

Tank is 20 gallons system volume (20Long connected to 12 gallon sump). This is an SPS dominated system although right now the system only has 4 small frags and some xoanthids colonies. Ca is 420, Alk is 3.88meq/l, mg is 1350ppm. Keep sg at 1.025 w a refractometer. Temp is almost always around 80F. No detectable Po4, and Im using salifert test kits.

Lighting is a 250 watt AquaMedic Ocean Light pendant, bulb is a 14k phoenix bulb DE. Claim and everything were carefully acclimated to this light over the course of weeks, with screens and height adjustment.

Light sits about 14" off the surface of the water right now.

Clam sits at about 7" from the surface on the rocks.

Do weekly water changes, usually 4-5 gallons, Hob AquaC Remora on 24/7. Dose Reef Plus 1ml 2x a week monday and thursday. Feed fish every other day SF bay brand frozen variety pack dif cube with the exception of the emerald entre cube every feeding.

Thanks for any help.

 

[mbbuna]

i bet if you changed that 14k to a 10k the color will come back

 

[10" Red Devil]

Ack,

Really why would that make a difference?

Thing is, that this bulb makes everything else look awesome.

Thanks.

 

[mbbuna]

Croceas come from the reef top where they get a full spectrum of light ( 5k to 10k). bulbs in this range have more usable energy then the 14k so the clam doesnt have to keep a ton of zoox(whats making it brown)to be able to feed on.

 

[10" Red Devil]

So the spectrum of light where they come from is in the 5-10k region, hmm and this is the only reason why it is darkening? I will get a picture for you so we can get a 100% confirmation.

Anyone else keeping croceas under 14ks having this problem?

Thanks.

 

[mbbuna]

this is how clams use light to feed. they basically farm zoox,they house them in there mantle,feed off of there waste and off of them. if there not able to get enough strong light for the zoox to reproduce at a rate to sustain the clam,the clam will uptake more zoox or let them grow into a large (for lack of a better word)group.with this larger group that is reproducing slower the clam can still farm the zoox and live. and with this larger group you see the brown for 2 reasons,1- the clam stops producing it natural color shield so the zoox can have access to the light.2-this allows you to see the zoox(the brown)

 

[10" Red Devil]

this is how clams use light to feed. they basically farm zoox,they house them in there mantle,feed off of there waste and off of them. if there not able to get enough strong light for the zoox to reproduce at a rate to sustain the clam,the clam will uptake more zoox or let them grow into a large (for lack of a better word)group.with this larger group that is reproducing slower the clam can still farm the zoox and live. and with this larger group you see the brown for 2 reasons,1- the clam stops producing it natural color shield so the zoox can have access to the light.2-this allows you to see the zoox(the brown)

I understand Clams need light in order to feed. However I question whether or not it has anything to do with the color of the light or not. In fact I started a thread over in the sps keepers section and there are quite a few people who have had croceas under 20k-14k bulbs with positive experiences.

Anyone else?

 

[mbbuna]

I'm sure that there some that have had success, and here in the clam forum i see some that have success with that lighting but i also see a lot that have the same problem that you are having. Clams don't work like SPS, SPS uses there Zoox to just feed off of there waste,and SPS are single celled animals .
check out this thread.

http://www.reefcentral.com/forums/showthread.php?s=&threadid=706560

 

[Snprhed]

could you get the temp down to 78 consistently? I don't think it is the problem but it could contribute. Also mb and I don't always see eye to eye on bulb temp (k) however with a change like that it could very well be a lighting issue.

 

[10" Red Devil]

Snprhed,

Change like what?

It has always been under 14k lighting.

 

[jay24k]

I'd give it some time. There is nothing wrong with the kelvin range. Plenty of people I know keep them under 14K-20K and imo aren't going to make a clam brown up. I would possibly move him up but if he bleached out, it will take awhile for it to color up. If he is extended and no pinching, just be patient. Also, I have to disagree on the temps. Most reefs are above 80 anyway and mine is around 82-84 on the hottest days and my clams have no issues. Stability is the key and right now, that's what it needs.

 

[10" Red Devil]

Well it is about 20" down from 250de pendant and attached to the rock where it is. It has completely retreived all of its xooa that it had prior to the bleaching event. But like I said it was darkening before the bleaching event and it is still dark, so I dunno I am at a loss at this moment.

 

[Snprhed]

I was referring to the "browning". I think he does look pretty good also. Jay is probably right keep it stable and give him some time.

 

[Snprhed]

Ammendment to last post.

Disregard my last statement about looks pretty good. I was thinking about the other post talking about brown spots. The rest of it is good to go.

That is all. Carry on

 

[mbbuna]

if the clam has been getting more brown with time, i dont see how more time will make it less brown?

 

[jay24k]

Well, if you compare it to my SPS, I had alot of bleaching when I switched over. Many of corals got brown and several got a dark dark brown. To me, maybe he meant brown as a lighter brown and now it is a full blown brown.

I honestly don't see how a 14K DE Phoenix bulb will not color up a clam. If you can't keep a clam under that, then there are going to be alot of upset people here. Clams are different, however, just to give you a time frame, my sps took about 2.5 months before the brown turned back into color. The more you stabilize the tank and make em happy, the faster it will take.

 

[mbbuna]

i don't understand why people equate clams to SPS corals,there totally different. clams house 10 time the zoox per sq inch then acros(im not just making that up,its a fact)clams eat the zoox and there waste(they need bright full spectrum day light so the zoox can reproduce fast)acros just feed off the waste of there zoox.clams(especially croceas, maximas)come from shallow reef tops, where over thousands of years they have adapted to full spectrum light, there bright pigments are light filters that help protect the clam and its zoox from very intense light, if a clam is dropping these pigments it trying to expose the zoox to more light,so the zoox can reproduce faster so it can eat.people get amazing colors from acros with 20k lighting. what is happening there is they are bombarding the corals pigments with a focused blue wavelength of light (depending on the bulb 480nm to 500nm)
this forces one pigment to become dominant so they get these great colors,but unfortunately clams don't work that way.

 

[jay24k]

Where did I equate them to SPS? Quit being so defensive.

If you READ my post, I said, Clams are different, however....

I was informing him TIME is needed and a clam isn't going to color up in a week. They need bright spectrum, but I've seen plenty of people care for these under power compacts. AND I've seen them being cared for under phoenix 14k which ALOT of people on this board have.

Having said that, light is very important, however a 14K bulb is not going to turn a clam brown under MH because it is 14K. If you think otherwise, do a search here and see that maybe 10% of the clam owners on this board use 10K's. If the clam is regaining it's zoox, it WILL turn brown. You basically stated that in your post, so I'm not sure why you are busting a nut over this.

 

[mbbuna]

you equated them to SPS in the first few word of your last post,then you said later on that they are different.

I'm not being defensive, I'm stating facts. the clam in question was turning brown before the heater problem.

the only person i see "busting a nut"is you

I'm sorry for trying to help some one out with what i know about clams.

 

[jay24k]

Say what you wish, but I just gave my experience on what I know and have read about clams. Where I compared it to a clam was it turning brown after bleaching which unless I'm incorrect, they do. Other then that fact, they are in fact different which I stated.

How about we agree to disagree. I didn't mean to get in a ****ing contest so I'll just drop it here.

But in all reality, I think patience and time will tell. Could a 10K bulb help it faster? I suppose it would as a 10K is generally more intense. However, in my personal opinion, it should color up fine given time with your 14k bulb.

Good luck with it and let us know how it does.