Clams and bulb temp question

rjung1

New member
Looking for thoughts about lighting for a 55 gal setup designed primarily for clams and possibly some SPS. In an article by Knop in Jan 1998 Aquarium Frontiers, he says: "I strongly suggest that lamps that produce light with values over 10,000 K not be used for giant clams." He goes on to suggest that most farm raised clams seen in stores are best adapted to 6K to 7K range bulbs.

A LFS has a pretty good deal on an Aquastar-like setup with 2 HQI double ended 150 watters supplemented with 2 40 watt NO FLO actinics. The HQI's are 6700K. You can get the bulbs upgraded to 20K which I thought was a no-brainer until I read Knop's comment. I thought the 20K's would be better looking aesthetically overall, and better for the other stuff that will go in the tank, so I'm curious as to other's experiences with 10K or 20K's and clams.

Also, I could go another route and get 2 175 watt single ended 6700K or 10K bulbs.

It seems that I would be fine with 6700K bulbs but I do not like the pictures I have seen using this temp (too yellow!! ) Need thoughts from experienced clamers please.....
 
Re: Clams and bulb temp question

Originally posted by rjung1

In an article by Knop in Jan 1998 Aquarium Frontiers, he says: "I strongly suggest that lamps that produce light with values over 10,000 K not be used for giant clams."

Knop has always favored daylight lamps for Tridacnidae because of the relatively shallow depths of their natural environment. However, notice that he is only objecting to values over 10,000K.

A LFS has a pretty good deal on an Aquastar-like setup with 2 HQI double ended 150 watters supplemented with 2 40 watt NO FLO actinics. The HQI's are 6700K.

If it is truly a pretty good deal, go for it. But you may not like the color.

You can get the bulbs upgraded to 20K...

Why can't they upgrade to 10,000K? The 150w 10,000K HQI DE lamps have a lot more intensity and PAR than the 150w 20,000K HQI DE lamps. In fact, the 150w 10,000K HQI DE lamps are much stronger than the 175w 10,000K mogul base lamps. And for a 55-gal tank they would be more than adequate for SPS and clams. For a larger tank the 250w size would be better.

Here is what Daniel Knop wrote in his 1996 book Giant Clams:

"As a rule, however, only daylight lamps should be used. Colder light temperatures, however, can be useful and lately metal halide lamps with a stronger blue spectrum appeared on the market. These lamps with Kelvin values of about 10,000 produce light conditions very similar to those found in the coral reef in several meters depth. A tank illuminated with the new type of metal halide lamps does seem to be less bright in comparison to the conventional halide source but this is due to its lower green-yellow spectral components comprising the range around 550 nm. This range appears especially bright to the human eye. Such a lamp with about 10,000 Kelvin can be used as the sole light source of an aquarium. Certainly the future will bring further improvements."

"In the case of daylight lamps with 5000 to 6000 Kelvin, it is advisable to correct the spectrum by adding blue fluorescent tubes."

So, there you have it, you can go with 10,000K secure in the knowledge that Daniel Knop would approve of your choice. He would not approve of the 20,000K.

I got 10,000K HQI DE lamps instead of 6500K Iwasaki lamps (my second choice) because I really liked the color of the 10,000K better and because you don't need as much actinic supplementation. So if you can get that setup with 10,000K HQI DE lamps plus the NO fluorescent tubes and it is a very good price, I think you should get it. I don't think you will be happy with the 6700K lamps and I don't think the 20,000K lamps will be strong enough by themselves or provide the best spectral distribution for clams.

Good luck,

:)
 
Ninong, thanks very much for the detailed and informative response! I also don't understand why the LFS does not offer an upgrade to 10K bulbs. I will press them on that more. If they will do it, I think I will get the light setup. Thanks again for helping me make an informed choice.
 
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