Do I have TOO MUCH lighting?

[donna2933]

I have a 75 gal. reef tank with inverts, corals& etc., however, the mushrooms are not doing to good. I have 2-175W metal halide (10 & 12K Blueline) and 2=40W fluorescents (1=20K & 1=blue). All 4 lights are on during the day at the same time. Is this too much light for my aquarium size or should I rotate the lights being on? The 2 metal halides are hanging about 7 inches above the aquarium and positioned in front, the 2 fluorescents are at the back. I had planned to purchase another pendant metal halide, but do I need it?
Thanks!!! Donna

 

[mr . salty]

I believe the two you have are more than enough. You should probably put them on a timer for a few hours during the middle of the day.This will simulate the sun at high noon. Leave the flo's on from about 9am to 9pm.STEVE

 

[donna2933]

Mr. Salty
Based on what you said about my lighting, I should only leave the two metal halides on a couple of hours in the middle of the afternoon. I have been leaving the metal halides on all day along with the fluorescents. Will my inverts, corals & etc. get enought light with just the fluorescents on and only using metal halides a couple of hours? Before I bought metal halides, I didn't have enough light and my corals and inverts were dying. I'm going from one extreme to the other!! I just wanted to make sure that just a couple of hours of metal halides was going to be enough light for what I have in the tank.
I had the mushrooms on the bottom of the tank, however, they were still directly under the halides and may have been getting too much light for too long a period of time.
Thanks!!!! Donna

 

[mr . salty]

Donna, I run my MH from 11am to 3pm. STEVE

 

[reptilicus]

Donna,
DO NOT GET ANY LESS LIGHT!!!!! If I were you, I would definitely go with the 3rd pendant, the more lighting the better IMO. I have 400-watt MH's plus NO actinic fluorescents (I would get VHO but can't get them over here, planning on ordering them from the US) over my 180-gal, more light just means more options in terms of what corals you can keep. 175-watts is the absolute minimum from SPS and clams. I know people who have 15-10 watts per gallon and more over their tanks and they can keep everything. If something looks like it's getting too much light, just put it under a ledge or somewhere where it's getting more indirect light. There is no such thing as too much light in the reef, even 400-watt MH do not give as much light as a coral reef would receive. Believe me, get the extra light you will not regret it. Your results will be so much better.
Regards,
Tom

 

[donna2933]

I am a little confused as some of you seem to think I don't have enogh light and some say too much light, so I guess the next question is to determine how long I should leave the 2 metal halides on during the day? Mr. Salty says about 2-3 hours during afternoon.
Thanks!!! Donna

 

[mr . salty]

No one has said anything about the heat yet.Three 175's over a 75gallon is going to rais the temp conciderably. This is something else to consider.STEVE

 

[broomer5]

I would agree with the others here. Move the mushrooms to lowest part of tank/rock, most indirect light you have. I would start backing off the duration the MH's are on during the day. Most agree that you don't want to make lighting changes too rapidly, but rather in smaller incremental stages. Try reducing the time the lights are on by a half hour a day or so. Consider running your flo's as usual. Watch the inverts/corals ... they will let you know when the lighting is right.
Broomer

 

[donna2933]

Thanks for all the input on my lighting. I will start reducing the time on the metal halides and go from there.
Mr. Salty was talking about the heat factor of the metal halides and my tank stays around 80 degrees, however, I have three fans to cool the aquarium if necessary.
Thanks again!!!!! Donna

 

[reptilicus]

Basically you want to end up with somewhere between an 8-12 hour photoperiod, just make sure you increase the light levels slowly. When I upgraded from 175 to 400-watt MH's, I started off with them at 3 hours, and increased by half an hour every 2-3 days until I got it up to 9 hours.
With regards to heating, the fans are more than enough I have no trouble keeping water temp OK with fans even though I use 400-watt MH's. I know a guy who uses 400-watt MH's plus VHO over his 55-gal, he bought a chiller and doesn't use it (lives in San Francisco) because the fans are sufficient.
You will be fine.
Regards,
Tom

 

[donna2933]

Should I alternate the 2 metal hadlies and turn them on at diffrent times? I have been turning them both on at the same time. I start with the fluorescents and about 4 hrs. later I turn the halides on. I have been operating all the lights for a total of 8-10 hrs. At the present time, everything in the tank has been use to both halides being on at the same time.
I appreciate all the info all of you have given me and it has helped a lot.
Thanks Bunches!! Donna

 

[donna2933]

Thought of another question regarding ny lights. The two fluroscents are actinic and a 20 K, since the halides are a blue spectrum, do I need to use full spectrum bulbs for the fluorescents? Donna