Lighting Colors and Kelvin

[nautafish]

I am replacing my 4x65 watt PC with 2x175 watt MH and 2x54 watt HO 03. I have a mixture of fish and coral in my 75g, 48" tank. My question is between the two MH lamps, what K rating should I get? I was thinking of one 13K and one 20K. The LFS said the 13K was really close to bright sun light and the 20K gives off a tinge of blue. Otherwise I was just going to get both in 20K.

 

[loganj]

I wouldn't mix the MH bulbs because your tank will have one side more blue than the other. What most folks use, if they have actinics, is 10k bulbs. A 13k bulb is nowhere close to sunlight...sunlight is about 6500k and has a yellowish tinge to it. The 10k bulbs will give you a white light. 20k MH's with actinics, IMO, is going to be VERY blue and I doubt you'll like the looks of it. My advice would be to buy your bulbs online and start with 10k bulbs. I think you'll get a much better price on your bulbs that way. Be suspicious of advice from the LFS...they don't always know what they are talking about. JMHO.

 

[nautafish]

Loganj, thanks for the info. I will probably use the MH for daylight use and the 03 for Dawn/Dusk use. Is this ok? If so, should I get both the MH at 10K?

 

[Thumper]

For the record I usesd a 14 k in between two 10 k bulbs and it looks funny. I'm going to go back with a 10 k in the middle with my actinics.

 

[nautafish]

Looks like I am sold on getting both the MH at 10 K to start off!

 

[Sparky]

I use 2 250 watt MH @ 20K....and 4 actiics...I love they way it looks.

 

[Thumper]

Usually I'm running 3 250 watt mh and 440 watts of actinic's

 

[loganj]

You can start the actinics earlier than the MH and let them run later if you want to for the dawn/dusk effect. Don't turn them off when the MH comes on though...leave the actinics on.