20k for Acros

[Chuck239]

I am currently running a mh 250w 14k pendant about 12" above the water line. I have a 20k Ushio lamp coming in tomorrow to see what it does for my sps color. My plan was to lower the pendant to 6 or 8 inches above the water to compensate for the lost par. Does this seem like a reasonable set-up/sufficient light for my coral. I'm just worried about the low par of a 20k lamp and my acro's not getting what they need. I've listed my tank setup and coral below.

39 gallon display
20 gallon sump/fuge

blue acro
green acro
pink birdsnest
frogspawn
zoas
xenia

 

[madcow]

I'd check out Sanjays lighting guide before lowering anything.

http://www.manhattanreefs.com/lighting

 

[kevinpratt823]

I'd send the Ushio back and just get a Radium. You wouldn't have to lower your light, and you'll get better growth AND color. There's a reasom just about every high end sps dealer(like Tyree)uses them.

 

[KSC]

The reflector and ballast/bulb combo has far more impact on growth than the color temperature. Get a Lumenmax or Lumenbrite reflector and you will have par to spare.....

 

[Reefried]

i think he has a double ended pendant so the radium is out of the question.....and if so then run a new phoenix 14 k and lower the fixture.......ushio 20k us the worst bulb for par/ sps color.........i run a 250 watt phoenix 14k over a 37 gall tall and have sweet sps colors, and my reef optix 3 reflector is about 4-5" off the water line and only likie 3-4" above the tank rim.............


...i think your problem is that your pendant was too high to begin with.............and trust me about the ushio 20 k thats the bulb i started with and thought that sps up high would be fine and that the 20k wouldnt fry my lps/softies, but what happend was that my lps /softies were fine and my sps were brownish green and lacking any sort of POP, and that was with my pendant in the same place it is now(low 4-5")

 

[Chuck239]

Thanks, great info/tips. I will lower the pendant and try the pheonix 14k lamp.

I have a Hamilton Cayman Sun reflector and magnetic ballast, it came with a Hamilton 250w 14k lamp and I've seen very little growth and poor sps color over 3 months. My levels are all good, no detectable phosphate or nitrate so it must be the light.

 

[kevinpratt823]

Thanks, great info/tips. I will lower the pendant and try the pheonix 14k lamp.

I have a Hamilton Cayman Sun reflector and magnetic ballast, it came with a Hamilton 250w 14k lamp and I've seen very little growth and poor sps color over 3 months. My levels are all good, no detectable phosphate or nitrate so it must be the light.

I believe the Hamilton puts out decent par, but if it's old(8+ mos) it won't be, and you really won't notice the difference by eye.