Derasa in established soft coral tank

[heitlagerm]

Greetings,

Have 80 gal. 20 year old reef (most stuff moved from 150 gal reef, about 10 years old at the time)
Filled with one large frogspawn and large softies (see pic., though ear leathers, toadstool leathers, kenya trees, green sinularia, and palythoa i have thinned out on right side since pic. was taken, to make room for more more lps and clam)

Does anyone have experience with such a set up with small Derasa (2-3 inches)? If so, what contributed to success - if any? (Besides taking into consideration, flow, light, stable params & within range (temp, kalk above 400, KH about 8.5, Mg above 1200), activated carbon use (BRS premium rox .8), Target feeding reef hype phyto for last 3 weeks (which it seems to suck up).

Have had the one in pic from aqua SD since 2/11. No growth (no white edge) , no change in color, fully expands during day, closes at night. Noticed since the addition caulerpa has been dying off in refugium (Phyto addition or clam filtering water, or other possible cause)

Just looking for some experiences with a similar setup and things I might be overlooking

 

[bluemon]

Although the lack of a white edge seems a bit concerning, I see no problems with the setup!

In my experience, the most important thing in clams is getting a healthy specimen from the get go. And if it lasted two months, it probably was a healthy specimen.

Did you notice a healthy foot and white edges when you bought it?

 

[Mr. Mojo Rising]

There is no mention about your light... some people give their soft corals very low light, others provide higher light. Soft corals can grow in any range of light, but clams still need a certain minimum level. IME light is more important than parameters.

 

[heitlagerm]

Although the lack of a white edge seems a bit concerning, I see no problems with the setup!

In my experience, the most important thing in clams is getting a healthy specimen from the get go. And if it lasted two months, it probably was a healthy specimen.

Did you notice a healthy foot and white edges when you bought it?

Thanks for reply. Actually yes. As a matter of fact it has attached to glass bottom a few times, as recently as a week ago, but then moved itself again. I discovered it had attached before after flipping on side. I did decrease the flow since then (need to probably turn one pump off. It's mantle wasn't really moving though but sometimes a tiny bit. The pumps alternate from opposite sides) Now it has just moved slightly in last 5 days. I do try to leave it alone when it moves.

Also, attached is a pic I just took for further references from falf way point in tank.starting at huge greensinularia on left. It is pretty empty now to make room for future additions. At bottom is latest clam position. (Excuse the glass)

 

[heitlagerm]

There is no mention about your light... some people give their soft corals very low light, others provide higher light. Soft corals can grow in any range of light, but clams still need a certain minimum level. IME light is more important than parameters.

Thanks, I have considered that as well. Don't have a PAR meter. The Frog spawn and other lps are lower in tank. But I know they don't require as much light as many sps do either. Do have a tiny sps frag near top (see previous pic).

I have been ramping up the levels gradually more over the last weeks.

Just FYI, like I said this tank is 20 years old. Lighting system was installed in 2010 as a DIY (weren't any good options then) and last year upgraded many of the LEDs. I am using a hurricane x controller, connected to Apex from 9 to 9, ramping up and down over 1 hour each.

Have separate white, blue, uv, royal blue and red/green channels kicking them up a little bit each time (4096 levels of dimming). Trying to not shock the system, by drastic changes.

Sorry for lengthy responses. Hope it provides info needed.

 

[heitlagerm]

When I bought it, it did have bright white edges.

 

[twentyleagues]

Derasa clams are one of the lowest level of light clams but still need quite a lot to thrive. Bottom end would be high for most soft corals 150-200 par with 200-400 being a more optimal range. Par meter rental may be an option.

 

[minus9]

Judging from the pics of the corals in your tank, I'm guessing too little light. Clams can hold on for a long time and get nitrogen from filter feeding, but it's never enough to sustain them long term. It's rather simple, they need quality light and plenty of it. The clam is starving to death, so unless you change/add lighting or move the clam to another tank with adequate lighting, it will not survive long term.

 

[heitlagerm]

I tried putting him on shelf where trachyphylia is now. Corralled him with strategically placed rocks but still moved a lot and jumped off. It didn't like it there. I wonder if I can put him higher up at level of frog spawn. Problem is, flow is stronger there. Also need to keep him from jumping. Just hate to fiddle with him too much. But i guess killing it where it is now isn't an option.

 

[minus9]

I tried putting him on shelf where trachyphylia is now. Corralled him with strategically placed rocks but still moved a lot and jumped off. It didn't like it there. I wonder if I can put him higher up at level of frog spawn. Problem is, flow is stronger there. Also need to keep him from jumping. Just hate to fiddle with him too much. But i guess killing it where it is now isn't an option.

Derasa are not found on rocks, if they're found on solid surfaces, it's the reef flat or sandy bottom. The are the second largest clam, so they get large and don't stay attached for very long. I think you have two choices, either provide the right amount of light or move it to a tank where is has the proper lighting. Your solution for moving it higher is only temporary.

 

[exnisstech]

The first thing I would so is try to get ahold of a par meter. I bought one just because I couldn't keep clams alive long term. I found out I was starving them even though to my eyes it looked like plenty of light. I added a small derasa and gave it 300 par on the bottom and it thrived. It more than tripled in size before it succumbed to a broken hinge :crying-face:

 

[heitlagerm]

Based on majority of responses I will assume lighting is primary issue. Just wanted to rule out other possible problems first.
Ordered a good enough par meter, based on most reviews, here and youtube (you will guess which one. Clearly not Apogee $$$), so I can have a basic idea. Arrives Friday.
I will keep you updated.

Thanks for all your help!

 

[heitlagerm]

Derasa are not found on rocks, if they're found on solid surfaces, it's the reef flat or sandy bottom. The are the second largest clam, so they get large and don't stay attached for very long. I think you have two choices, either provide the right amount of light or move it to a tank where is has the proper lighting. Your solution for moving it higher is only temporary.

My rocks are pretty flat and big. Might be able to create a sandbox on one of the levels to create pretend reef flat - After I get my readings

 

[minus9]

My rocks are pretty flat and big. Might be able to create a sandbox on one of the levels to create pretend reef flat - After I get my readings

That might work for a year or two, but derasa can grow 1-2" a year if not more, so that cute 3" derasa will get big quickly, plus the weight as they put on mass at the base of the shell. Some things to consider going forward. If I haven't mentioned it before, buy James Fatherree's book on clams, I think it's a must have for clam keepers.

 

[heitlagerm]

That might work for a year or two, but derasa can grow 1-2" a year if not more, so that cute 3" derasa will get big quickly, plus the weight as they put on mass at the base of the shell. Some things to consider going forward. If I haven't mentioned it before, buy James Fatherree's book on clams, I think it's a must have for clam keepers.

Thanks! I figured it would be temporary, but it gives me some time to figure out options.

 

[rhitee93]

As a data point: I have two derasas that are doing well in the 200par range. From what I've read, I wouldn't want to go much lower than that.

Here is my big guy, it's over 9" now. Most of the growth between that weird ridge in the shell and the edge has happened since I bought it in July. These things grow fast.

This is the eventual replacement. The big one will outgrow this display in a year or so, and I wanted another large clam for that spot, so I bought this little 3" one last month. It always has a clean 1/8" of growth on the shell as well.

Both of these clams are on my sand at ~200par at peak of the day. That was measured with a SenEye, so take the numbers for what they are worth.

 

[heitlagerm]

Awesome! Are you going to eat the big one? clam chowder.
Really appreciate the data points. Helps me to see what is could expect if conditions are right. No doubt will help someone else as well.

Need to get that PAR meter. Should be in this week.

 

[heitlagerm]

@rhitee93 When you say peak of the day, how long do you provide that level of light each day?

 

[rhitee93]

@rhitee93 When you say peak of the day, how long do you provide that level of light each day?

The peak light level last for about 6 hours. Here is what my settings look like (Thanks to the nifty BeanAnimal Noopsyche programming interface!)

 

[heitlagerm]

Update on Derasa. I have growth now!!

Since I have had a DIY led light hood since 2011, I updated it. I can now get at least 150 par or more at the bottom.

First, temporarily, I had placed it closer to the top on the rock. That resulted in the first growth edge a couple of months ago. But then as I was changing out the leds the growth, for obvious reasons stopped again.

After I did the update I gradually increased intensity. Still not at 100%. In last week or so it began to show a new growth edge.

It is still on a lower rock. It attached itself so I haven't moved it. But it looks promising! Thanks again for all the help!