Photoperiods?

[Nykademus]

I recently (this past weekend) made the switch from PC lighting to MH/VHO lighting because I finally finished my canopy. The tank is a 90 gallon and the sump is located in the basement and is 55 gallons, so heat issues should be minimal.

I went from 260w of PC to 720w of MH/VHO (dual 250 MH 10k, dual 110 VHO actinics)

I am wondering how long people leave their "daylights" on for. I have heard and read many different things on this and have thus far planned on leaving them on for about 7 hours a day (with sunrise and sunset being an hour each) after the corals are acclimated to the increase, for a total of 9 hours of light each day.

Too much? Too little?

[Iraf]

what I'd do but I don't have a MH solution yet so hopefully someone else can chime in

[Tangster]

I get by with 6hrs aday with the 400w M/H and 16 on the VHO's At the coral shop we run them M/H 14 hrs ad and the VHO 18 hrs aday in the winter and summer the suns helps lower the time the M/H run. But like I said 6 hrs will most likley do just fine and the VHO will do there jobs at about 14 in a home aquarium.

[paulg]

I run my MH`s for 6 hours and my CF for 12, then my LED`s at night. I dont think you need to run your MH`s any longer then 6 hours, 4-6 is good, anything over that is just dumping heat into the tank and useing unwanted electricity, IMO. I have a 90 as well with 765 total watts. 2/ 250 MH and 4/ 65 w PC with the rest made up from the LED moons

[wildreef]

Originally Posted by Nykademus

I recently (this past weekend) made the switch from PC lighting to MH/VHO lighting because I finally finished my canopy. The tank is a 90 gallon and the sump is located in the basement and is 55 gallons, so heat issues should be minimal.

I went from 260w of PC to 720w of MH/VHO (dual 250 MH 10k, dual 110 VHO actinics)

I am wondering how long people leave their "daylights" on for. I have heard and read many different things on this and have thus far planned on leaving them on for about 7 hours a day (with sunrise and sunset being an hour each) after the corals are acclimated to the increase, for a total of 9 hours of light each day.

Too much? Too little?

I my self run MH's.
I would suggest no more than the amount of hours you are running now,
7 to 8 hours seem to be the amount of time every one i know here.
I used to run like 10+ hours a day but Ive seen no diffrence in coral health
running them more. ( if not better )

And i would start to get brown diatome algae when the photo period was longer than 8 hours.
Ive had no problems running 7.5 hours daily now for the last 2 months+ i would say.

You'll save money to and less agravation from nuisence algae's that seem to thrive on all that light any ways.

[Nykademus]

Sounds good, thanks for the replies everyone!

[Tangster]

Originally Posted by wildreef

And i would start to get brown diatome algae when the photo period was longer than 8 hours.
Ive had no problems running 7.5 hours daily now for the last 2 months+ i would say..

Either you do not have a diatom bloom and some other problem ? Or you do have them and you have a water parameter Issue ? Lighting period would have no effect on the diatoms they are feeding on your water's problem.. After the initial cycling and a new set up diatoms are gone for good . Unless you keep adding a life giving carbon source for them to live off of You may want to check in to your own water problem's if it is indeed diatom blooms ?

If your theory any coral culturing system's like the one that I manage or any of them would be over ran with a diatom problem as we run lights almost 24 a day . to generate the corals growth. I've never had or have a diatom problem there or at home once they where gone at start up .

[Bogie]

I haven't had any diatoms since after they died after my tank first cycled either. Maybe you have a different problem due to bad water parameters, wildreef...

[wildreef]

Originally Posted by Tangster

Either you do not have a diatom bloom and some other problem ? Or you do have them and you have a water parameter Issue ? Lighting period would have no effect on the diatoms they are feeding on your water's problem.. After the initial cycling and a new set up diatoms are gone for good . Unless you keep adding a life giving carbon source for them to live off of You may want to check in to your own water problem's if it is indeed diatom blooms ?

If your theory any coral culturing system's like the one that I manage or any of them would be over ran with a diatom problem as we run lights almost 24 a day . to generate the corals growth. I've never had or have a diatom problem there or at home once they where gone at start up .

well the brown algea get's on no where but the back glass, I did how ever cut down on photo period ( amount of time ) and thus it seems to greatly reduce the diatome issue.

Would you think something else might be causing it ? such as ?
Over feeding has not been an issue.

The only thing i can think of is the MH/'s bulbs need changing, they are getting some time on them. ( more time on'em than i want )

[Tangster]

Originally Posted by wildreef

well the brown algea get's on no where but the back glass, I did how ever cut down on photo period ( amount of time ) and thus it seems to greatly reduce the diatome issue.

Would you think something else might be causing it ? such as ?
Over feeding has not been an issue.

The only thing i can think of is the MH/'s bulbs need changing, they are getting some time on them. ( more time on'em than i want )

If you have diatoms ? in your system stimulated by the lighting period I know you have a water issue What it is ? Diatoms are very specific and particular as to what they use for a food/energy source , As for what maybe causing your problem ? I have not a clue maybe its your water filtration system, for the water to fill the tank ? As for bulbs age ? I run mine two yrs mine here are 18 months old now