lighting

[MM WI]

nice to see a bit of movement away from the repeated claims that tridacna require MH lighting in this forum.

As encouragement to anyone wanting to keep clams it can be done under PCs T5s CFs if you have enough bulbs and change bulbs before they get too old. The other much smaller difference I see in my personal experience is the common suggestion that croceas require more light and are more sensitive than Maximas, Croceas have proven much more robust in my experience. I cant remember the last time I lost a crocea, It has been well over a decade without lossing one, and I keep them under standard 65K bulbs made for home lighting with vho actinic. I use about 400 watts of daylight on a 125G with a couple of 6' actinic vho bulbs. If a newb came in here and suggested keeping clams under these lights they would get shot down for sure.

For anyone thinking of adding tridacna I suggest in the neighborhood of six vho bulbs or eight t5ho bulbs the full lenght of the tank would be enough to meet the lighting needs of tridacna. Each clam will be a little different so you can move it up or down in the water to see if it likes more or less light.

- Mark

 

[BrentB]

In the recent 2009 Annual edition of Marine Fish & Reef, there was a very good article on triacnids.

I was surprised to read the following

"The less-light-demanding clams include T. derasa, T. gigas, and T. squamosa. These two (?) species can be successfully kept under T-5 lights or even power compacts. But they do need to be placed close to the light source (say within 10 inches from the lamps."

It gave me some hope that I might be able to keep a clam in my 30 gal with power compacts.

Thoughts?

 

[ludiNano]

I kept my first clam, a squami in 10g for a year+, w/ 96wpc 50/50. I got increadabe growth, faster than i had expected. I had it in top 1/3 of tank.

Ive moved it to my 29g upgrade w/ 150w MH sunpod 12k w/ 65w PC, still has great growth. Sits on bottom.

 

[quicksilverq]

This is great I agree with you all. I am sure you would be fine brent with a hardy type of clam. the squamosa should grow a little slower than the gigas and derasa untill you up grade it.

 

[dbartkow]

I am considering adding a crocea to my 29 gallon Biocube with 144W of PC lighting. I just ordered a Quantum Light Meter to take readings a various depths in my tank. I was wondering if anyone has done this with their tank? I would like to compare readings with someone that has seen good growth out of their crocea. Let me know what PAR values you come up with.

Thanks,
Dave

 

[BrentB]

Light Meter?

Light Meter?

<a href=showthread.php?s=&postid=14082905#post14082905 target=_blank>Originally posted</a> by dbartkow
I am considering adding a crocea to my 29 gallon Biocube with 144W of PC lighting. I just ordered a Quantum Light Meter to take readings a various depths in my tank. I was wondering if anyone has done this with their tank? I would like to compare readings with someone that has seen good growth out of their crocea. Let me know what PAR values you come up with.

Thanks,
Dave

Dave,
Does the light meter work underwater? Or do you use it along the sides of the tank? Can you post a link to a site where one can be looked at or bought?

BTW, thanks for all teh great responses!

Brent

 

[dbartkow]

Yes, the light meter has an attached sensor that can go under water. It is different then a light meter that works for a camera. This measures the photosynthetic ability of the light - which is what you want for coral.

Here is a link with more info:
http://www.apogee-inst.com/pdf_files/QMSS.pdf

I'll post more info later this week when I get it and I take some readings.

Dave

 

[quicksilverq]

Tell me what you get after you do it. this sounds intresting.

 

[dbartkow]

I will take the readings over the weekend and let everyone know.

Thanks,
Dave

 

[IslandCrow]

I'll post some readings when I get home tonight. I don't currently have a crocea (I had to sell it when I deployed), but I kept one for a little less than a year under my current light setup. It had good growth (especially for a crocea) and excellent color, so I'm guessing it would have continued to thrive. It was under T5s, though, so you're probably not going to see the same numbers in your tank. Where it was in the tank, I'd guess my PAR was around 250.

 

[dbartkow]

Thanks Mike. How deep was the clam?

Dave

 

[tomndeb]

go for it

 

[dbartkow]

Mike,
Did you get a chance to take any light readings?

Dave

 

[IslandCrow]

Sorry, I completely forgot, and now I'm back at work. I've actually already taken the readings. They're just on my computer at home. The clam was about 8" underwater and the lights about 5" above. My current clams are two derasas that are about 12" underwater. Assuming I remember tonight, I'll post my PAR readings for those as well.

 

[dbartkow]

Thanks, Mike.

Dave

 

[IslandCrow]

OK, just as I was thinking, my PAR when I had the crocea would have been right around 250. Since I didn't have a PAR meter at the time, I'm deriving that from the approximate depth when I did have the clam under the identical lighting. Right now, my derasas are getting PAR of 152 & 156 respectively.

 

[dbartkow]

Thanks, Mike. I will take my readings this weekend. It am looking forward to seeing the comparison.

Dave

 

[crvz]

I've got crocea clams on the floor of my tank, lit by T5 bulbs, that get light measuring on the PAR meter of ~200 or so. Been that way for years without much of an issue.

 

[dbartkow]

Thanks for yor input. Have you seen much growth with that light level?

Thanks,
Dave

 

[dbartkow]

Crocea and PC Lighting

Crocea and PC Lighting

Well I got my quantum light meter and took some measurements over the weekend. First a little info on my system. I have a 29 gallon BioCube with 4x36 lighting upgrade by nanotuners. It is basically 144 watts of PC lighting. For comparison, I took measurements with different light bulb configurations that I have.

Here are the readings with the first configuration:
50/50, 10K, Actinic, 50/50

Here is the 2nd configuration:
I swapped a 50/50 out for another 10K
10K, 10K, Actinic, 50/50

Here is the final configuration:
I swapped out the Actinic for another 50/50
10K, 10K, 50/50, 50/50

In summary, it is clear that the actinics really don't provide much beneficial lighting for the corals.... although they do make them look better.

Also, the lighting with PC bulbs is much more powerful in the center of the tank. It drops off as you go towards the edges of the tank.

Finally, while the bottom of the tank may not be a good location for a crocea, the upper 1/3 of the tank (with the right selection of bulbs) offers plenty of light for the clam to do well in.

Now I just have to go out and get me one

Dave