Originally Posted by microman2k
it's about time to replace the bulbs in my Coralife 36" PC fixture..i am not sure what kind they have in them now (this is my first time replacing them)...so what kind should i get? looking on the internet..i have found these types of lights..which combination should i use?
20,000K
10,000K
Actinic
50/50
i dont really know the difference in these..so i need a little help!
20K=blue (with pc lighting skip it, not powerful enough. sometimes used with MH to get a blue look. even with MH corals grow slower)
10K=white/daylight (get it for one bulb replacement. best compromise for coral growth, looks and algae containment. 6500k looks dull in comparison)
actinic=420nm is true actinic sometimes called actinic 03, although anything up to 460nm is sometimes sold as actinic. 420nm promotes coral pigments which protect them from harmful UV rays. 420nm looks purple and dull to the human eye. also promotes coraline growth. IMO current usa's dual actinic is the best choice. one side of the bulb is 420nm which is effective and one side is 460nm which looks absolutely GREAT when combined with a 10K bulb. 420nm alone wont add any noticable color to a 10K bulb of equal wattage, you only notice it with the other light out. do yourself a favor and get the current dual actinic. cost a little more than no name e gay bulbs (like $35 online) but worth it for looks. get it as your second bulb.
see the green mouths on the polyps, with just true 420nm and 10K bulb the green doesn't show at all. with the dual actinic it does
with just the dual actinic 420/460 bulb the whole center turns green except the rim. with just a 420nm the tank is still too dark to see much
50/50= just a combo of actinic and daylight. usually 420nm and 10K but you have to look at the specs. If your fixture only had one bulb or you never want to run the actinic and daylight bulbs seperately you could run 50/50 bulbs
