metal halide light

[arn]

Hi, I recently added a 175watt 55k metal halide light to my 60g tank. Now, all my rocks are starting to turn green. Can anyone tell me if this is normal or if it's not, what should I do next?...Thanks

 

[kennynj]

ARN,
I'M NOT SURE YOU HAVE THE TEMP.
VALUE OF THE BULB CORRECT. IF IT
IS IT'S MUCH TOO LOW. AT THAT TEMP
IT A GREAT GROW LAMP FOR ANYTHING
GREEN. DEPENDING ON THE MANUFACTURER
THE TEMP. RATING SHOULD RANGE FROM
6500K AT THE LOWEST AND DEPENDING ON
HOW BLUE YOU WANT THE COLOR THE TEMP.
RATING GOES UP TO 10000K, 14000K, AND
EVEN 20000K. WHERE DID YOU GET THE BULB?

 

[arn]

oops.....its 175watts 5500k metal halide.

 

[dad]

How long are the lights on? What are your water readings? What did you have before the MH's?
There is alot of questions to ask.
Give all the details you can,

 

[arn]

ive had the metal halide light for a week now...i use to only have flourescent bulbs (50/50 and blue actinic bulbs). Now, I have all 3 of them.....the lights are on for about 8 hours to 12 hours a day..... But recently, I noticed that instead of the rocks turning purple, they are turning a bit green....i need help here....thanks guys

 

[dad]

First I would cut back on the time the lights are on.
6 to 8 hour a day intstead of 8-12.
Because you added so much light it will encourage algae to grow.
I am not an expert by far,
Are you adding any chems? and what? Do you check calcium levels?

 

[toadstar]

Every time you add extra light, the extra light will encourage algea to grow. You can't do anything about it. Reduce the length of the light, or try to remove the rock and scrub the green stuff off. I added new light lately and I have the same problem. I scrub the green stuffs off using a toothbrush to allow the other beneficial aglea to grow. Just be careful, you don't want to harm your coral as well.

 

[arn]

ok thanks for the info.