Upgrading my metal halides

[brattramp]

After one year of 2 250W metal halides 15K and now that I've started more SPS, I've decided to upgrade to 400w metal halides 20K. So far, in my corals, my greens/oranges and pinks are fine, but the blues and reds tend to turn brown.

Here are my tank specs: 55g, (4 ' x 2' x 14"), lights are in the hood about 14" from the tank. There's no space for atinics

Do you SPS experts think moving to 2 lights at 400w 20K is a good move for stronger coloration?

What ballast and mogul bulbs would you recommend?

It's a big investment, so I just want to be sure. Thanks!

 

[House of Laughter]

I would investigate other parameters like phosphate before investing in new lighting - the corals should color up under that set up (assuming they aren't at the bottom of a 30" tank).

Water quality is key, lighting comes second to that IMO

House

 

[Cloud1921]

I agree with House, water quality is the key.
Your tank is only 14" high, 250w halides should be sufficient for growth and coloration.

Red and blue do pop in my tank.
My tank is 30" high and I use 10k 250w halides.

 

[2Sunny]

Second that motion . . .

This little SPS is under 250 watt 10k lighting and is well known as being one that requires "intense" lighting. I believe that in years past 400 watts was necessary to compensate for water that was not as "crystal" clear as we get today with advanced husbandry techniques. I agree - focus on all the other issues in SPS care before spending money on lights. For what it's worth I have gone from 1000 watt bulbs to 400 watt bulbs to my present system with 250 watt XM 10k bulbs.


HTH - Joe

 

[jhale]

what ballasts are you using now, and what type of reflectors?

I agree in a 14" high tank 250's should work well.

 

[brattramp]

Thanks for all your feedback guys.

I should have been clearer: The tank is 4ft long, 2 ft tall, and 14 " wide. The hood, and bulbs are 14" above the top of the tank. i.e. corals in the tank can be up to over 3 ft below the bulbs.

As for water parameters, they are consistently (and I just checked again):

salinity 1.026-1.027
temperature: 78-80 degrees
Ammonia: undetectable
Nitrate: undetectable
Nitrite: undetectable
Phosphate (seachem kit): around 0.01-0.02
Calcium: 480
Alkilinity: 8 dkh (I had not dosed alk today before I tested, but just added alk moments ago, so it now should be a little higher)

The light specs are:
2 x 250 W XM Mogul Metal halides
ballasts: ARO
No actinic (no space in the hood)
Reflectors: Not sure what the brand is - no label on them
Photoperiod: 7 hours

Do you all still think 2 250W bulbs 15K is enough? My concern is that 1) some corals are 36" below the lights, and I have no space for actinic supplementation, so I'm wondering if 2 400W bulbs 20K might be better.

Thanks!

 

[Killerdrgn]

2x 250w bulbs should be more than adequate if you want the lighting to be more intense get lumenarc reflectors. the 400w bulbs may bleach the corals.

 

[reefman]

two 400 watts on a 55 gal is over going to do more harm than good. bleaching is not the only worry, heat will have u running the chiller full strength. n i'm assuming your electric bill is 1 fix price.
like evry1 says, water quality is key. spend your $ n energy on keeping po4 low n ca/alk stable.
btw: if your bulbs r over 9 months old, i would change them. old bulbs lose intensity our eye will not notice. this may cause browning too.

 

[brattramp]

Thanks, guys!