once again... sps lighting...

[insanity4224]

Hey guys, love the site so far good work.

my new tank will be 200cm long, 70cm deep and 80cm high and has about 1200litres(just less)/250gal.

I want to keep various sps corals and i will using 3x 250watt halides
(2x XM20k's and 1xiwasaki 6.5k). I beleive 400watt halides are overboard...

I have two questions:
a) How high should i place the light unit (assuming some corals will close to the surface)?
b) Will i get a 'two tone' effect with the different K lights? what i mean is will the center of the tank be more yellow than the sides due to the middle halide being 6.5k(for coral growth) and the two on the sides being 20kblue?

-jason

 

[MarineTeng]

i think the middle 6500k with two 20k's on the outside will make it have three sections of color, if you want it to be the same color throughout the tank i think it's better to use all the same MH's and then having actinics for the blue color

 

[AOAndy]

Yes I think the colour difference between the bulbs will be very obvious. Best to stick with all the same color temp bulbs if you can.



Andy

 

[LakeEd]

Jason,

Place the lights so they are about 8-10" (20-25cm) above the water surface. You don't want the possibility of water splashing up on them, and at this distance it also allows you to get in under them carefully to feed.

As for if you will notice a color difference in your tank... ohhhh yea, a big one! Y&ou will see both ends being very blue, and the center much more on the yellow side.

 

[kevinpo]

Hello,
Welcome to RF
20-25cm is the correct distance for the lights. The color difference between 6,500K and 20,000K is quite noticeable. Not so much between a 10,000K and a 20,000K. Also the type of reflectors and orientation of them will have an effect. If placed end to end you will get more separation of the bulb color and close side by side less separation.

Cheers,
Kevin