Is 5 hours of MH not enough?

[jfingers8]

I have a 90 gallon dominate SPS tank my current lighting in the Elos Planet 2 fixture. 2x 150 DE MH and 4 T-5 39w bulbs. I run my T-5's for 12 hours a day and was running my MH for 6 hours because things were looking pale and now since i cut it down to 6 things are looking a lot better. My question is can i go down to 5 hours or should i stay at 6?

 

[mike_cmu04]

If things are looking good I would not change anything 6 hours is a good amount of time.

 

[sedor]

You could go down to 5 if you really wanted to. Personally I run mine at 6 because all I use is the halides and I don't always want to be staring at a dark tank. 6 hours is about the amount of time i'm down around the tank so it always seem alive to me. They say that coral only uses the first couple hours of uv anyways so 5 should be plenty.

 

[IFbettas]

I've been running my halides for 5 hours per day for the past year, and have had good results. I do not run any supplemental lighting either.

 

[Gills 619]

My 2 400w 20k only run 4.5 hours and have better growth than when I ran at 6

 

[zangmann]

I run at 5 as well, everything is AOK. There was a thread here somewhere where reducing the photo period to around 4 hrs actually helped quite a bit.

 

[ms123]

I run my halides for 5 hours a day and 2 t5s for 10 hours with great results.

 

[yeloowtang]

interesting info:reading:

i run mine for 8h 1x 250MH 10k and t5's actinics for 12 h everything is growing well and nice colors,now wondering if i would have better color with less ??? and more growth
i might try to cut back 30 mins every two weeks to see what happens

steff

 

[jefathome]

There was an article in one of the online mags that showed the photoperiod/reproductive cycle of Zooanthellae (sp?) to be about 5-6 hrs... or so I recall.