can i the MH turn on and off 4 times durign day?

[manuelink]

hello! can i turn on and off, 3 or 4 times at day a MH illumination of my tank? i have photosynthetics corals! the reason is because i want to simulate the sun with clounds and to bring less hours of live to my MH ligthing! and the actinics will be on all day!
my MH: 400w 20,000k with a coralvue ballast!

i ask because i dont know if it is posible to do without impair the MH

[clownfish_09]

If i can remember right as long as your MH's are on for more than 30 mins, and you let them cool for more than 10 mins before you turn back on you should be fine. It might cause more wear and tear on your lights and ballast from turning them off and on 3 or 4 times a day.. But im not sure, but anyone correct me if im wrong.

[xJake]

IIRC the great majority of residue (almost ubiquitous to 'soot') builds up on the interior of the bulb each time the bulb is 'fired' or turned on. This residue is what causes color-shift and decreasing levels of PAR. So, I wouldn't recommend it. I know there are systems such as ACLS from Sfiligoi that are able to dim MH lighting as a way to simulate cloudy days as well as sunrise/sunset. These systems can be expensive, but if you really want to simulate cloudy days then it's the only proper way to do it.

If you turn the bulbs on and off 3-4 times a day then your bulbs will probably wear out 3-4x as fast with little noticeable benefit to your animals. It's a bit like a car engine; the majority of the wear-and-tear on an engine happens during the first few miles of driving. So, multiple, short trips will do more damage to your car's engine than a single, long trip. This same concept is true for aquarium water pumps - if you repeatedly turn them on and off throughout the day then they'll wear out much more quickly.

[manuelink]

thanks both! so i'll keep the lighting turn on all time, poor of my corals they'll go to see the sunny all time!!

what about keep the MH ligthing only 3 or 4 hours turn on all day?? in spite of 9 hours
i've heard about this and the corals are with the same color, same growing with only 4 hours of MH illumination

its true or fake?

[E.intheC]

I've heard of some people going for 2 or 3 days with the lights off every month or every other month to simulate a storm, and they've had great effects. I wouldnt' do this on a daily basis

[manuelink]

interesant! i think lights off one day every week to simulate as you say a storm! it will be great! only keep the actinics of course!!

what can you say

[ludiNano]

Ive read on RC some where and at LFS that corals need at least 6 hrs dark pierod to procces days intake. I've tried it from the start of my tank, i get great growth and really extends viewing times.

Lighting 150w MH 12k--- 65w PC 10k/420nm/ moon lights.
On 3am - 9am Off.

On 3pm - 9pm Off.

[manuelink]

Originally posted by ludiNano

Lighting 150w MH 12k--- 65w PC 10k/420nm/ moon lights.
On 3am - 9am Off.

On 3pm - 9pm Off.

and now you are doing in this moment the same photo period?

what lights are on at 3am to 9am and 3pm on to 9pm off
i didnt understand very well

[ludiNano]

The exact light goes

6- 1w Blue moons on 24/7

6- 1w White moons On 2:45 Am - 9:15 AM

1-65w PC 10k/420nm On 3:00 AM - Off 9:00 Am

1- 150w MH 12K On 3:15 AM - Off 8:45 AM


Same at night sarting at 2:45 pm w/ the white moons agian. I dont consider the white moons as much contributers to cound that 1/2 hr.

[manuelink]

wow so you turn lights on at 3am? in the middle of the night?
here the sunrise is at 6am so im starting actinics 6am to 8pm
so, thanks for the idea!!

[ludiNano]

Yea morning for me, get up at 3.30 to work 5-3

[reefscape15]

Turning a MH bulb on 4 times a day would use more electricity than leaving it on all day so energy savings is out the window with that idea. Also when the Solaris LED system came out, i thought that simulating storms was a cool idea, but then started thinking a diferent way. If you have a completely controlled environment for your corals, why wouldn't you want the effects of full sun every day? More growth, better colors-i will admit maybe a little less natural, but what system of animals in a box is natural?- Just my way of thinking. If you can provide the near perfect growing environment, why would you want to interrupt that cycle?

[reefscape15]

sorry i forgot to mention, startup on a MH bulb draws a ton of current as compared to current draw once the light is fully lit

[kfennell]

Originally posted by reefscape15
Turning a MH bulb on 4 times a day would use more electricity than leaving it on all day so energy savings is out the window with that idea. Also when the Solaris LED system came out, i thought that simulating storms was a cool idea, but then started thinking a diferent way. If you have a completely controlled environment for your corals, why wouldn't you want the effects of full sun every day? More growth, better colors-i will admit maybe a little less natural, but what system of animals in a box is natural?- Just my way of thinking. If you can provide the near perfect growing environment, why would you want to interrupt that cycle?

There is NO WAY that this is true, how are you an electrician

Say that the MH drew ALL the power that a circuit can provide (it doesnt), and its a 20A circuit and it does this for a minute (it doesn't).

You would use .037 KWh to start the light.

With a 250w MH you use .25kwh per hour so you need to turn it off for 8.9 minutes to match the unimaginable worst case scenario.

[reefscape15]

K fennel-*** is your problem? I'm sorry to tell you that it take way longer than 1 min to start up a bulb. Current draw is almost 2 times the amount on startup (which is about 10 min-starting at a very high rate and declining as time goes on), and when it is not recommended, in my opinion anyway, that you have MH on more than 6 hrs a day, that you would be cutting your total run time to 4 hrs a day. Also the true 20k color would take at least 30min to come out after the bulb cooled for 30min, so run time at true 20k would be minimal, therefore making it kind of pointless. I'm just letting this person know that he would see no electrical savings by doing this. Take it easy and please find something better to do with your time than badmouth people on a forum.

[kfennell]

You are wrong

There WILL be electrical savings there won't be a net savings, but it is absolutely NOT due to the start up voltage, do you have a kill-a-watt meter? Put it on your MH when you start it and when it is running, there is not much difference. If it was wouble, turning on a 1000w MH would trip a 15 amp circuit every time.

[reefscape15]

??? whatever dude...i guess your the so called "expert" huh?

[madadi]

for what its worth, i run my lights for 3hr on 2hr off 3hr on 2 hr off 4hr on. starting from 8am till 10pm. colors are definitely darker but growth is the same which is good for a 20k bulb. i also run my fuge light 3hr on 3hr off for the entire day and night cycle. chaeto is much darker and its actually growing well for once. i have not noticed a difference in bulb life but i have no meter to take accurate readings.

[madadi]

oh and the reason i tried this light period is because i only have one MH bulb over my tank. no actinic bulbs and when the bulb was on for the entire day straight, corals got really light and growth stopped. darn lumenbright reflectors!

[manuelink]

so the coral growth stopped when you had the mh running all day?
i have only one mh too and actinics
but i prefered to turn off the mh once a week hope to have the same results that you in growth

because if i turn on and off every 3 or 4 hours its possible to waste the life of mh, im not sure but just its a hunt!

[madadi]

my MH bulb is a 400w in a lumenbright reflector and its super bright! after two months of acclimation to the new reflector the corals were still light in color. i was thinking of getting some actinic bulbs so i can reduce my MH photo period and still be able to look at the tank but decided to turn the bulb on and off throughout the day and give the corals a brake from the light. not sure how much damage this is doing to the bulb but its time to order a new one and ill see how fast this bulb needs to be replaced. if it seems like its hurting the bulb, maybe ill get some supplemental actinic light. if not, then ill keep it the way it is because i like the results so far.

and yes, as strange as it sounds 12-14 hours of MH light really stunned the corals growth. i here i thought the more light the more growth. now im doing 3hrs on 2 hours off 3 hours on 2 hours off 4 hours on. i can view the tank in the morning, between work and school, and after work.

[jener8tionx]

I don't know about wear and tear, but you could create a track or pulley system that just moves the light up and down to reduce or increase the intensity of the light.

[2 TAZ]

I have my halides turn off when the tank gets to warm, sometimes the bulbs turn on and off many times per day, I have not noticed a reduction in bulb life, although I do not have a light meter.

[manuelink]

that's a good reason to turn on and off the bulb
i'm sure many people who has a controller temp do the same with the MH
but are you sure you dont have a reduction life to the bulb?
i think is to difficult to know if it reduces the bulb life or not

[MileHighFish]

I run my Mhs 5 hours a day VHOs on 12 hours, color and growth are very good. When I lived in So-Cal and was paying $300 a month for electric bills (an apt) with the chiller running on and off all day I considered doing the on-and-off thing just to avoid the chiller running so much which in return caused the A/C to be running all day. It was a vicious cycle. I now live in NM and in 5 months the chiller has not clicked on once so that as been a nice advantage. Plus it cost me about $50 a month to run the tank here!!