Actinic and MH bulb combinations can I change it?

[Delphinus]

Yeah, your wattage wouldn't change but the output lumens might. You could go with the 12k's and probably get the look you want without the actinics, but the flip side to this is you are likely going to discover that the 12k's have less intensity than the 5500's.

I used 14k's (175W) as my first set of halides when I went to halides. I really liked the light they put out but they didn't really do much for the corals. Coral growth improved when I went to 10000K's. Yeah the overall blueness went down but the colours and the growth of the corals intensified. To me there is no difference between 14k's and 12k's they are just a different brand.

Most tanks I've seen lit by 12k's look nice. I'm not knocking this bulb. But they're not the bulb for me.

Incidentally, I am still using 10k's. I got used to the colour very quickly and I'm quite impressed with the intensity. My new tank, whenever I get my microbubble problem solved, will be lit by 2x250W Iwasaki 6500's and 2x110 actinic blues to offset any potential yellowing. I have heard good things about this combo but since I haven't tried it yet myself am not sure what I will be looking at NEXT year.

My recommendation to you for now though (just to throw in more confusion), is to try 10000K's with whatever fluorescents you want (actinic or otherwise). You'll probably like that combo very much. The light that a good 10k puts out is a "crisp white". IMO you don't need actinic supplementation, but if you did go with that, you'd probably have a good combo with the right amount of "slight blue" that people like for that "ooh wow" factor and a good amount of whatever light corals and the like are using for optimal coloration and growth.

Ultimately, this is a hotly contested issue. There are many different opinions but they are all valid. You need to find out what works for you and if you find that then run with it. [img]images/smiles/icon_biggrin.gif[/img]