View Full Version : Dusk/Dawn effect with Metal Halide
jadendo
11/24/2012, 10:42 PM
Guys/gals,
Please help. I want to have the dusk/dawn effect for my tank but don't know how to get this done.
This is what i have over my 120 gallon tank
2x 250W mogul base Metal Halide
2x 24W actinic T5
I run the T5 24/7. The MH is turned on for 6-7 hrs a day.
Thanks a lot
altolamprologus
11/24/2012, 10:53 PM
Halides can't dim on and off like LED's can. The best you can get is have your t5s turn on one at a time, then each halide turn on one at a time.
s_kelley
11/24/2012, 10:55 PM
I'll second the one at a time t5 suggestion
Skipponator
11/24/2012, 11:02 PM
I'd cut the t5 time down by 12hrs so the fish get a break. A good night's sleep. Depending on livestock, tangs for example, 24/7 light may cause them to stress and ich from lack of sleep, I've seen it a few times. Throw the t5 on a timer. If you want a true dimmable solution then look around for some sort of led supplementation .
jadendo
11/24/2012, 11:17 PM
So i should only run T5 before during and after the MH are turned on, correct?
Then turn off the T5 a couple of hrs after MH are off right? So i should leave my tank pitch dark at night or should i have some sort of moon light?
I used to think Actinic is for night time. Wow! I feel stupid now. Thanks for all suggestions.
Skipponator
11/24/2012, 11:30 PM
In my halide days I would run vho but I feel t5 with a good actinic bulb would be better. I'd run my actinics 2hrs before my halide schedule, all through, then 2hrs after halides(with 15min intervals between firing and off to simulate rise/fall). With 15min intervals between each actinic bulb to simulate dusk/dawn. Then at night I'd run moonlight LEDs or nothing.
Now, with my LEDs, I run a schedule with lunar option , and on my r5 I set the actinic a an hr apart from the daylights. I also run my blue/UV Oraphek tube early and later than the t5s. The AI Vega is on its own ramping program so I can't precisely mention the Oraphek program I made. But I always have actinics on during all of my main lighting programs. Its always worked well for me. If that at all makes sense? If I need to break it down I can tomorrow when behind a computer rather than a phone. ;)
altolamprologus
11/24/2012, 11:32 PM
Oh I didn't even notice the t5s are on 24/7. Just shows how well I read before replying lol. Anyway, as said above, the fish need a dark period to rest every night. Could you imagine how stressed you would be if the sun were out 24/7 and you couldn't close your blinds? And too much light is just as bad for corals as not enough. You'll likely see a marked improvement in overall health and growth after giving them at least a 10 hour dark period each day. Moonlights are not necessary, and are mostly just for aesthetics.
jadendo
11/25/2012, 12:20 AM
All your feedbacks made a lot of sense. Thank you so much. I will let my fish go to sleep tonight. Poor guys. The damn actinics have been on for months.
jadendo
11/25/2012, 12:27 AM
Here is my revised light schedule:
12pm: actinic on
2pm: MH on
8pm: MH off
10pm: actinics off
Tank goes dark until the next day
I don't have a lot of control, so what do you think of it? Thanks
Skipponator
11/25/2012, 12:35 AM
That looks great and you'll likely see a positive difference in your aquatic friends!
grcforce327
11/25/2012, 07:47 AM
I do what others are suggesting.Two of my T5 actinics come on first,then the other two,then the halides.When the last pair of T5's turn off,a pair of 6-bulb led strips turn on for moonlight.
jadendo
11/25/2012, 10:01 AM
Guys,
I notice that during the pitch dark hours, all the softies and zoas are closed.
The only things that are open are the anemonies, the birdnest. Is this how it is supposed to?
I thought they have to open and feed at night?
BigAl2007
11/25/2012, 10:13 AM
If you've been running your T5's 24/7 for months it's probably past time to replace them. On a 8-10 hour photo period at normal wattage (not over-driven) you'd want to look at replacing them around 10-12 month period. 24/7 I'd say replace them in 4-5 month period.
When you do replace them do so in "steps" of about 2 weeks apart. Example:
T5 bulb (a) replace this week
2 weeks later T5 bulb (b)
zakstrong
11/25/2012, 02:29 PM
they make dimming halide ballasts. would be more expensive switching up your timers but i've always wanted to try them.
http://www.aquacave.com/CoralVue-250W-DIMMABLE-Single-Metal-Halide-Electronic-Ballast-P2355.aspx
shifty51008
11/25/2012, 03:48 PM
yes it is normal for corals to close up during the night some corals have feeders that will come out at night but those are diffrent.
jadendo
11/25/2012, 10:43 PM
The fishes now have a 12 hours of darkness to sleep. They must be saying thanks to RC.
alton
11/26/2012, 07:00 AM
All the 0-10v dimming ballast for MH are 208 to 277v. I have not found one that is 120v. I think Coral Life made one in the 90's called solar system. It was a 175w electronic ballast with a medium base pulse start lamp that worked great. You could set it to take 2 hours to ramp up and shut down. It worked great with Reeflux lamps. When mine took a dump I tried to get David at CoralVue to make it, but he was not interested.
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