Crocea Help

[Hobster]

Hoping someone may be able to help with one of my Croceas. I have 2, both purchased at the same time 6 mths or so ago. Both are a little larger than a clenched fist. They sit on very large clam shells (from the beach) on the bottom of a 75g (corners) with 2 x175 mh and 2 x 96 pc. One has not been extending his mantle and stays almost closed most of the day. Some times it is extended a little but not to the extent that the other is. Parms are: ph 8.2, alk 3-4 meq/l, Ca 400. temp 80. SG 1.025 (refract) Even though not fully extended it still reacts to light change (shadow) I do not know what to do for him. My tang does bother him at times but does the same to the other clam and that one could care less. From what I have read, it appears to be somewhat like pinching but I am not sure. Any ideas ? Thank you.

 

[Scuba Dog]

Slowly start moving the clams up closer to the halides up in the rockwork, they are starving for light...you can also feed to some live phytoplankton Dts to help build of there energy levels...Croceas are the hightst light demanding clams...under 175s they will need to eventually be high up to get as much par as possible...

 

[Hobster]

They are both exactly the same distance from the bulbs. One is thriving and fully extended the other is not. They are up on a DSB so they are fairly close to the light. All the SPS are doing well so I am thinking something other than a light issue.

 

[Hobster]

Anyone?

 

[jda]

I am with Scuba Dog. 175W don't penetrate as well as other MH. Might be your problem, might not. What will it hurt to move them up (if you have the room).