Which "K" for my MH bulbs?

[SeaHorse_Fanatic]

Also, check out the 10000k Coralvue Reeflux bulbs. They are a very bright white with a hint of blue. Much nicer 10000k than many other bulbs I've seen on tanks (many have a hint of yellow). Also you get the higher PAR readings of 10000k, which your underlit system could probably benefit from. Many of the higher k bulbs sacrifice PAR for blue light aesthetics.

JME,

Anthony