XM 250W DE 15K or 20K?

[RonPeter]

Has anyone here used either of these bulbs? I am thinking of getting one of these bulbs in the Bulk Reef group buy and am curious what these bulbs are like. How blue is the 15K? Any opinions or pics would be appreciated. Thanks.

[Abbyreefer]

from what I've read teh par rating for some reason on the xm 20k's are better then the xm 15k bulbs. heres a link.
http://www.reeflightinginfo.arvixe.com/tabular-lamp-data.php?Watts=175&LampManuf=Select+Lamp+Manufacturer&Lamptype=Select+a+Lamp+Type&LampName=Select+Lamp+Name&BallastName=Select+Ballast+Name&Shielded=Select+Shielded&tfm_order=DESC&tfm_orderby=PPFD

[fkshiu]

All the reviews I've read including Sanjay's favour the XM20K over the XM15K both in terms of colour and PAR.

[RonPeter]

Thanks for the info everyone. :)

[RonPeter]

So I think I will try the 20K then...thanks everyone.

[robzilla]

is this for your big tank?