Clams - PC vs. MH (pix included!)

Hi, just some background before i start:

Background

first off, i purchased this clam (roughly 4.5'' ultra blue T. Crocea) knowing that i would upgrade to MH lighting. it was subject to PC lighting for roughly 2.5 months before upgrading to MH.

Setup & Equipment

PC setup:

- 88w of PC lighting (1x32w 10K, 1x32w 50/50, 1x24w actinic)

- Nano-Cube (12g)

- 9'' from light

MH setup:

- 150w DE MH (20K)

- Via Aqua (18g)

- 18'' from light (2x farther than the PC setup)

PC vs. MH

the pix that i took are roughly a couple months apart. the picture on the left was taken two months after being in the Nano-Cube with 88w of PC lighting. as i said before, i knew i was upgrading so the clam was then introduced to the Via Aqua a couple months later. after moving from 88w PC to 150w MH, the clam has shown significant mantle expansion, more vibrant colors, and overall appearance looks much better than with the previous lighting. colors changed from turquoise to electric blue, the mantle went from dull purple to a stunning blue as well. new growth marks have been seen upon upgrading and the clam looks MUCH healthier under MH as opposed to PC lighting. i would have to predict that if the clam was subject to the 88w of PC lighting for long periods of time it would most definitely diminish greatly in health and eventually come across death.

Conclusion

PC lighting is capable of keeping a clam alive in the short-term (under 6 months), but is NOT suggested for the long-term (6+ months). i think that the clam would not have survived more than 6 months under PC lighting. i highly discourage keeping clams under PC's solely based on first hand experience with coloration/size/and appearance of my clams.

no matter how strong your PC lighting is, it WILL NOT and CANNOT compare to respective MH lighting.

Pictures

- picture on left was taken 2 months after being subject to 88w of PC lighting. (this was how the clam looked 95% of the time, it wasn't "irritated" when the picture was taken)

- picture on the right was taken 3 months after being subject to 150w of MH lighting. (this is how the clam looks now)

- no alteration was done to either pictures, both pictures were taken using the same camera settings but under different lighting.

the pictures speak for themselves... for those of you contemplating on getting a clam under PC lighting, please think twice before you purchase a clam. try to give the animals that you purchase the best homes that they deserve under captivity

feel free to comment/criticize... thanks to those who actually read the post.

*EDIT* scroll down for pictures

Hmm, yeah nevermind. No clams for me. Not until I get MH's

Good post. Hopefully people listen.

I had always wondered: would it be possible to keep a squamosa in a healthy state under power compacts?

hey that's a nice clam! I think the only thing that would end this discussion is to find out exactly what kind of algae is in the clam, find out what spectrum and intensity of ight it requires and then trying to replicate that. Metal halide certainly seems to work well - but no one on this board has said why except that it is stronger light in general.

The reason why people are trying to keep clams under pc is because metal halide is so darn expensive!

Anyway, everyone has thy're own examples of clams doing this or that under different lighting, but what is really needed is some scientific data.

like i said, i think for any clam, it is possible (short-term only), but you would be running the risk & health of your clam as time progresses.

lower light clams like derasa/squamosa may fare slightly better than higher light clams like crocea/maxima under power compact lighting; but as stated above, if you want clams, get MH. PC will not suffice in the long run.

ps. thanks for the comments i agree we need more scientific data, all i can provide is "experience" data...

on another note, MH lighting is only slightly more expensive than PC lighting. if you can afford a reef-tank, you can afford MH.

hey btw... is your name from naruto? or is it actually your name.

naruto.

haha...

nice

hmm maybe I'll try and make a metal halide hood myself

How old was the PC lighting? If a clam doesn't need actinic your only comparing about 48w PC@10K to 150w MH@20K.

A further test would be 10K vs 20K MH to see if that had anything extra to do with it also 150w MH vs. 150w of 10K PC.

no matter how strong your PC lighting is, it WILL NOT and CANNOT compare to respective MH lighting.

PC lighting was relatively new (no older than 2 months). there are others considering about keeping clams under PC less than or around 48w (nano-cube DX -24w of 10k 24w of actinic) so the the lighting layout may be somewhat relevant to them. in most cases my 88w (48w of 10K) is more than most nano-cube setups.

this is NOT a definitive guide, and since i don't have all the $$$ and time in the world to test all lighting setups (if i did have time and $ i would, trust me), this is just ONE scenario. i realize that it may not be comprehensive and may not apply to everyone, it is enough to provide some sort of comparison for those contemplating the idea of a clam under similar wattage PC's

sorry for the "red x" pic, here's what the picture is supposed to look like:

update: i've been asked if the clam was fed, and the answer to that is yes...the entire tank was fed every 2-3 days with cyclopeeze, and the clam received about 1-2 direct but "gentle" squirts of cyclopeeze from the baster. i thought this was unecessary since the clam siphoned nutrients and food from the water column anyways... so it could grab what it wanted whenever it wanted

i've also experienced that feeding the clam isn't as important as lighting and water quality, obviously it is a nice supplementary form of nutrition but i would still suggest lighting to be the main contributor to health especially with larger clams (greater than 2.5'')

excellent post!

Originally posted by froomite

hey that's a nice clam! I think the only thing that would end this discussion is to find out exactly what kind of algae is in the clam, find out what spectrum and intensity of ight it requires and then trying to replicate that. Metal halide certainly seems to work well - but no one on this board has said why except that it is stronger light in general.

The reason why people are trying to keep clams under pc is because metal halide is so darn expensive!  

Anyway, everyone has thy're own examples of clams doing this or that under different lighting, but what is really needed is some scientific data.

Metal halides really aren't that much more expensive than PC's. My first PC setup, a 130 watt coralife fixture, cost me about $120. I have seen retrofit 150-175 watt metal halide setups for $150.

That and watch for deals (Ebay, local reef societies)...I just got my new 175w setup (reflector, socket, bulb, electronic ballast) for $110...cheaper than a lot of PC setups. You just have to be patient and wait for a deal.

Cheers,

Fred

odd side note. I have a clam in my 58g with a 250w 10k halide on there. I started with an ushio 10k( about 600 par) and didnt like the color that much so i got an XM 10k(about 900 par).

after about a week my clam and my leather for that matter both shiveled up. The clam looked much like your PC pic. After a month of this i put the ushio back in and after a week everything was back to normal. clam's mantle was about 2x more extened.

just weird....

Great post!

wow

That's the same clam!?

He must be very happy now

yep that's the same exact clam... the dates above are approximate and at most off by 1 week.

and as FAC_WNY said above, it's true that most MH can be found around the same price as PC setups, it's worth the wait and if you find a good deal, grab it! you will not be disappointed with the results of MH and your corals/clams/other livestock!

Great thread uchiha. Now it's time for someone to compare the other types of clams as well.

Great stuff, indeed.

Very much appreciated.

I will build upon your research, if I may. With Chris's help (nanocustoms.com), I will shortly have possession of a "cube" that will produce approximately 126w of PC lighting - maybe more if I can tweak it and keep the temps in check.

I have always been a total advocate of MH, and I still am. But I do hope that PC's can be proved to be more than sufficient for nano-reef purposes for even the most light intensive critters...

Because if "they" can't (PC's in ultra-small tanks), then spending the $$$ on "supplemental" PC's for much larger tanks would only have limited value in comparison to utilizing the same wavelengths via smaller wattage "supplemental" MH's.

The 126w+ tank of mine that is quickly forthcoming will provide a close proximity in wattage to the 150w MH that you are employing and may give a more accurate insite intoa MH vs. PC scheme, watt for watt.

For the sake of furthering our understanding and accuracy in our observations, I will conduct a similar procedure as you have so brilliantly have done, and expose the clam to the exact same conditions, yet first under 126+ watts of PC and then 150w MH to record the changes (or lack thereof).

My friend-

You are one of the main reasons that I cherish this board...

Thank you for your knowledge and sharing.

Joe Mac

This is going to stir up controversy, but my clam has actually shrunken a bit with my 70MH + 10T-5 Actinic when compared with the 126w monster..

it makes sense tho, since the wattage of the PCs are almost double that of the MH..

Chris

Great post! I think that when you look at the health of the first vs. second picture it is obvious that long term, that clam wouldnt have made it had you not added that halide.

The only question I have with his test on the two clams is if he tested them under the same conditions. Let me be brief.

Anyone that has taken a Statistics class will agree that in order for a good comparison to take place we need to test for and eliminate as much as possible confounding variables. We must have our control and our experiment under conditions where others could replicate the test and recieve the same results on another given day. This is known as validity and re-testability.

By doing so we create proven theorectical data that will hold true today and tommorrow, allowing us to make such statements and not just assumptions.

I am a big believer in MH, but also a strong believer in the power behind PC. I own a nanocube deluxe and have it with 102 watts total power and I will not concede that my clam lost his color due to just PC lighting.

I in fact have owned him under 1 month stock lighting 48 watts then I went to 78 watts for another month and then currently to 102 watts. The pictures I have are for both 78 watts and 102.

With an increase in wattage my clam stays more open and appears healthier. The only question I have for the test that were done under PC and MH, was whether they were taken at the same time of day.

That is, did the clam have time to pick up diffused daylight from the room on both accounts. You don't want to have the PC compact taken at 9am and then the MH at 12pm. You have a confounding variable in diffused lighting from the room.

I'm no professor but I do know that when I took my pictures at different times of the day I got different views.

I hope this sheds some light on future comparisons between the two types of lighting on clams.

102 watts taken at 10 am.

78 watts taken at 9 am.

I also think that a clam will respond differently with different sets of PC lighting. I have 30 watts of high output T-5 Actinic 03 lighting. Then I have 2 50/50 JBJ 24 watt pc. And lastly I have 1 24 watt Jali daylight 7,300K.

I will attempt to show you the difference between how much more responsive the clam opens with same lighting at 10 am then again at 2pm of continous lighting.

Mike