is it possible to overpower coral with lights?

my tank is a 65 wide so its only 36" long. The light I have on it is a 4' fixture with two 250w metal halides, 8 t5 bulbs with either 65w or 85w total and 12 moon lights. Is this to much light for my aquarium? could it be the cause of a few issues I have? (algae and some coral losing color) and yes all water levels are good. I checked them yesterday.


The only reason I ask is because I gave a small coral that wasn't doing well in my tank to a friend, and he put it in his nano with LED lighting. Within a few days that coral is flourishing. It has its color back and is growing already.

Is this huge powerful light to much for my tank?

 

Absolutely! High powered lights will bleach corals!!! Just to put that in perspective for you I have a 90 gallon aquarium with 4 54watt T-5HO's on it. Most of my corals(lps with a few softies) are in the lower half of my tank.(Including a Tridacna clam on the bottom.)With that being said I don't grow any sps which will tolerate (and most of the time need) much more light and flow.8)8)

 

It is prob not to much for the tank.The corals have to adjust to the increased light level.I would cut your photo period back.How long are your lights on now?

 

thanks guys! I just cut my light time from 12 hours to 8 hours a day. should I start to run only one MH light during the day?

since I started using this light my electric bill went up $40 a MONTH! I talked to Steve (the guy that owns the local fish store here) and I can get a fully dimmable LED fixture with the capability to adjust white and blue lights for $400. since I'm running nearly 600 watts of power now and the new light will probably be under 100 watts (guessing) it will pay for itself just in money saved in electric.

what do you guys think about that? think I could get $300 out of my light?


This is a list of my corals (all of them are frags)

Blastomussa wellsi blasto LPS
acid drop facia LPS
blue tip cerealis acro
bullseye austrailia duncan
pink delight zoa
indonesian acanthastrea acan
purple people eater LPS
passion fruit palythoa zoa
blastomussa wellsi blasto LPS
sunset millepora milli SPS
neo loripes acro
blastomussa wellsi blasto LPS

all purchased from "Reef Pets" on this site

 

You can always adjust the height of the light too if you don't have a canopy.

 

I already have the light a good 10 inches above the water. I have the light listed for sale on here and on the local craigslist. I plan on selling it and buying one better suited for my tank size

 

That's your best bet. Another reefer here had only 6 T5 bulbs over a 75g tank and was having issues with his SPS corals. He cut his lighting back to 4 bulbs with excellent results.

One major problem is that a lot of people think they can force-feed their corals with intense light and get fanatical growth, and as you have learned, that's just not the case.

 

I think a lot of people have trouble with too much light because they try to acclimate by adjusting the duration, not the intensity. Acclimating to intensity it much more important really. The proper way to acclimate it to lower the duration, with your light to 4-5 hours per day. Put about a dozen layers of window screen over the tank. Remove a layer every few days and then start increasing the duration. Many corals can benefit from more light, however, if they have not been exposed to high levels of light, it will take longer to adapt.

It's also not just light. Light while beneficial is also a stressor and stressors compound. So, a tank with other stressors will not be able to handle as much light. Insufficient flow, too much flow, nutrients, toxins etc... are all examples of stressors that can interact with light.

The only corals you listed that are particularly sensitive to light may be the blastos, duncans and to some extent montis. You may wnat to place these lower, or under ledges.

 

It's not just too much light, but it's inefficient for the length of your tank....you're paying for the excess wattage. You could always sell the fixture and get one that would fit your tank....or use the fixture as an excuse to upgrade to a bigger tank

 

The 250W MH, but the 8 T-5s should cover it, unless I'm misunderstanding something? I agree, it's tough to get a single MH to cover much more than a 24"x24" ares. The T-5s if HOs may be enough by themselves though, although I'm not quite sure from the description...