View Full Version : I'm changing from 15k to 20k bulbs, how should I acclimate SPS to this change?

09/16/2008, 08:08 PM
I'm going from 8 month old 250w 15000k halide DE HQI bulbs (2 total) to 20000k, is this going to shock my montis, birds nest and pavona, or will they be ok? How should I adjust the lighting to acclimate them to the new bulbs? Also running three 65w actinics 420nm. This is in a 110g tall, corals are a little less than a foot below the fixture.

09/16/2008, 09:00 PM
you are actually going from more light to less light so acclimation may not be necessary. 15K bulbs should have more par than 20K bulbs. 20K would be bluer and dimmer than lower kelvin bulbs.

09/19/2008, 03:13 PM
Depending on the specific bulbs, you could be going down in light like IOreefer says. But I would check the par levels of the bulbs in question on either Sanja's site or JBNY's site to make sure. There are some low PAR 15K's and some high par 20K's. If par goes up, you should do something like either cut back photo period or raise the light for a short while.