what is this

is this just a Hammer. and is it a big difference with 20000k and 15000k.

http://thumbs4.ebaystatic.com/m/mqag...3MZ8Jg/140.jpg

Looks more like a torch to me.

thats what they say it is. but looks like a hammer in color.

Hammers, frogspawns, and torches come in all different color combos. You can really judge what type they are just by that, it's more the shape of their tentacles or polyps that determine which they are.

Thanks Brian and how much difference in color betwwen the two bulbs. that picture was under a 20000k and im getting 15000k.

it's really hard to say, depends on the manufacturer of the bulb and type of ballast. One company's 15k will look different then another. Also, a 15k bulb will have different color when using different ballasts.

That's definitely a torch...and the 20k is just a tad bit more blue in color, while the 15k has a slight crisp blue tint. You get better coral growth with the 15k vs the 20k.

I was thinking more towards a frogspawn. See how bunched the extensions are?