Clams with just at 20K??

[Mad Scientist]

Has anyone kept clams under just a 20K bulb. I'm replacing my bulb soon and considering a 20K XM. I've heard that lots of people now think that clams need more blue light than was thought even a few years ago (after people looked at the clams' pigments more closely).

This is for my 30hex seahorse reef, it's illuminated by a sole 250mh pendant. I don't have any corals in this tank, just my horses and clams. I keep maximas, squmosas, and a dersae. I currently am running a 6500K Iwaki with decent results, but, I hate the color - looks wise.

Do you think my clams will suffer from a drop in intensity going from the 65K to a 20K or will they thrive with the increase in blue light?

Thanks!

 

[smy168]

I've been using 20K lighting for the past 1.5 years and my Clams have done wonderfully!

below link to pics

http://www.reefcentral.com/forums/showthread.php?threadid=349954

 

[Mad Scientist]

Thanks, is that 250 you are running and is it HQI?

 

[smy168]

Yes it is...250 Watt HQI DE MH at 20K. And it's really kinda new, I had the AquaSpaceLight 150 Watt at 20K and the Clams were fine but since the upgrade, things have looked much better! The only thing I have to say is beware of heat in a smaller tank, I have the light mounted 12 inches off the water and 25.5 inches from the sandbed where my clams are so the light reaches well and the daily temp changes are 78 degrees with no light and 83 degrees when the lights are on. I got lucky with that.