LED and my derasa

Hi! Im new to this forum bc ive had no luck on my normal one (so far loads mire info) I picked up my clam on 1/2/12 and he dosent seem unhappy and he's opening everyday. He was under MH and now under a blueline 120 LED, color doesnt seem as vivid as it was a few weeks ago and it almost looks like his edges are receding and possibly fading. I was wondering if anyone had any advice (light too intense, not enough light ect) I'm running a 60gal cube 20gal sump with vertex skimmer and he's placed in the substrate apx 21-22" down from light, pwc of 10gal weekly. Any advise would be great!!! Thanks in advance

Pics pics pics!!! That'll help us out a ton - a FTS (with your lighting), and some up close pics of the clam....

What kind of MH was it under?

I know it was a pendent style in a 90gal cube but further than that I have no clue, the clam was at my LFS for 2 weeks before I was able to move him to my tank so I don't know how much the MH would have impacted it. I'm on my phone now so when I get access to my laptop I'll add some fts and a close ups bc I don't see a way to do that via phone

Welcome to the site!!!


Pics would be great. It does sound like a light issue, but there's a ton of things it might be.

Is it attached to anything?

Did you get a good look at it's foot when you bought it?

Any small snails on or around it?

The Blueline 120w puts out a PAR level of 485 @ 12", and the number will diminish quickly the further down you go. The clam may not be getting enough light at 22" down.

I keep my Derasa on the sandbed, under T5's. The par level is ~200

Well since the site was down for the majority of the morning i felt the need to move my clam.. I placed him about 6-7" higher placing it at 15-16" down from the light. He gained some color and almost immediately placed his byssal for about an hour , then pulled it back. (should i try a piece of plexiglass epoxied to the rubble rock i have placed that he originally went for to give him a better surface?)

Forgot to add before (beginning of january) and now. Shows the receding edge i was talking about.. Hopefully im on the right track???

I don't think that little of a move will effect it as much as you'd think. It should be fine. However, I'm not a clam guy and only had one about a month. I gave up lol.

Umm i dont even know where id move him except to the very top, but then id be afraid of him falling somehow (pretty sure id get NO sleep lol) Hopefully ill see better results, Still worried about him not being footed.. suggestions??

he will place his food once he has happy - and don't worry about it being a flat surface or anything!

The real test is if the clam is still on the rock where he is now in the morning - clams move most at night, in an attempt to find a better spot for them to grow and be happy

He looks good tho - I wouldn't be too worried

Believe it or not, 6-7 inches can be a huge difference in par in a glass box I took some par readings not long ago, i will find the video and post it.

I would leave him there for a few days and see how he does. It's going to try and maneuver into a suitable position for flow, so keep an eye on him.

As for the receding, from the pic it looks more like growth. Derasa's will show "white" on the edge of their shells when new growth is occurring.

Coincidentally, I have the same clam. This is about 1.5 years ago, now he's 5-6"

WOW! gorgeous clams reanea and daimyo!

yeppers...proper lighting is so key! it does look like it's happier since you moved it reanea....how's it doing this week? any improvements?

The edges seem to be better but he still hasn't footed with the exception of the first night I moved him but his color is better (the edges are actually blue again but not vivid like I know they can be). I've been planning a nano tank to house a pair of clowns and a nem only.. Debating on moving him over there and see if he's happier once it's cycled bc it would be shallower. Would there be any reason why I couldnt move him.. (IE will the nem bother the clam?)

they nem would bother the clam if it stung it!! I'd keep the clam where it is - the nems get to 12-18", and that dang clam will get to 15"+ if you let it!!

Way too much for one nano tank if you think about future sizes

Clam looks good in the pics you posted. As long as its opening up, color is good and new shell growth i would let it be.

Originally Posted by reanea03

Umm i dont even know where id move him except to the very top, but then id be afraid of him falling somehow (pretty sure id get NO sleep lol) Hopefully ill see better results, Still worried about him not being footed.. suggestions??

I wouldnt worry at all about a derasa not attaching its foot. When they are smaller they will do that but as they grow they let go and rely on their mass to hold them in place.

derasas would prefer the sand, though. once it gets a bit bigger, it'll just wanna be in the sand resting comfortably b/c of its weight.

Originally Posted by shmoliken

derasas would prefer the sand, though. once it gets a bit bigger, it'll just wanna be in the sand resting comfortably b/c of its weight.

Hey Paul. How have you been?

People have been saying that derasa and gigas "prefer" the sand for years however there are many studies that show in the wild they are most often found up on the reef mixed in the branching sps. Nothing wrong with placing them or any other species of clam in the sand as long as there is enough light for them

been here and there, dealing with new doggie who is training us. back on topic, out of my 2 derasas, one attached to a rock for 2 weeks, let go, and is content in the sand. the bigger one never has had any inclination to attach.

Well I feel better knowing that neither of yours have attached either! I did wake up the other morning and he had jumped back down to the substrate.. I really don't feel like its getting enough light, should I look into adding an extra light in the corner he sits?? If so what would be a cheaper light to invest in?

You can always add more light if you want. If you want to put something just over the clam i would look at the par 30, par 38 type screw in bulbs. One of those types with the narrow optics to get the light down deep should help out a lot.