clam losing colour

[Geoff]

my crocea has lost a lot of its colour. it is just paler. it still extends beyond its shell a good inch or two. it is not gaping. other than the colour it seems happy as a, well, clam. (sorry had to say it) it is a 4" clam. the colour is uniformly paler. this is under 400w coralvue's.

my other clam is doing fine (maxima).

the only thing i can think of is that it is winter time on my reef so the temp is at 75. is this low for clams?

my alk was a touch low, but not unacceptable. 2mg/l it is now up to 3.5mg/l. Ca is at 425ish. all the other SPS seem happy also. this seems like a wait and see, but wanted to make sure.

G~

[MiddletonMark]

How new is the clam?

[Casey]

Geoff do you have a pic sounds like bleaching

[SaltBlock]

Casey, I keep hearing this term "bleaching," can you elaborate?

AEB

[Casey]

Bleaching can happen to a clam when its enviroment changes or you change salts temp flucuation,different additives added etc etc
usually part of the mantle will turn pale and it spreads slowly but is very hard to stop once started.Kinda like an sps when it gets rtn.

[SaltBlock]

Thanks Casey...

Sorry to hear about the clam Geoff,

AEB

[Geoff]

interesting, but not exactly what i wanted to hear.

i have had the clam for almost 8 months.

any info i can find on this?

G~

[Geoff]

some quick research i have done.

http://www.reefs.org/library/talklog...ts_081797.html

http://animal-world.com/encyclo/fish...99/fnc0799.htm

http://www.reefs.org/library/talklog...en_102500.html

some very good info in these articles.

G~

[aliendomain]

Geoff

Where in the tank do you have your crocea? I ask because croceas need more light than other tridacna. If you have the clam on the sand or toward the bottom of the tank I would suggest moving it higher in the rockwork. Also I have seen croceas change color when under different Kelvin bulbs. Have you switched the type of bulb or upgraded in wattage in the past few months?

AlienDomain

[Geoff]

i did change from iwasaki's to coralvues. there has been a lot of changes. i did move the clam up on the LR just to make sure that it is getting enough light. i would think 400w would be plenty on a 22" depth tank.

G~

[Paradox]

After I upgraded my lights significantly, my clam got paler. After a week or so though, it looks back to normal. Since mine returned to its normal color I havent thought much of it since.


D.

[Casey]

Hes probably ok then just keep an eye on him the 400 is plenty light

[Geoff]

thanks, i will keep an eye on it.

G~

[Eric P]

Hi Geoff, how long is your photoperiod?

[Geoff]

Hi Eric.

it varies during the coarse of the year. right now the MH above the clam is on 11-1/2 hours. this is on the short side. January being the shortest at 11hours. June is the longest at 13hours.

G~