How long for halide?

Acro Crazy · Jun 14, 2014

After a bit of a break I started a 60 gallon SPS only cube and am running a single DE 250 watt 14k metal halide bulb over it in an aqua medic combo fixture. I have been using LED's for so long i have lost my MH knowledge :neutral:.
Im currently running the bulb 8 hours on and im wondering if anyone sees any issue with running it at 12 hours a day? my goal would be increased growth. Any thoughts? Here's my tank so far.

Z-man · Jun 14, 2014

Not saying I'm right, but I run my halides for a 3 hour on, 2 hour off, 3 hour on cycle. The blues are on an opposite on/ off cycle from the MH with a total on time of 10 hours a day. I have good growth, although I have nothing to compare them to.

FL_Reefer · Jun 14, 2014

I run mine for 5 hrs a day

Acro Crazy · Jun 14, 2014

FL_Reefer said:
I run mine for 5 hrs a day

Hmmm, I guess I'm wondering if anyone sees a noticeable difference when running longer hours. If there was no growth difference between running 8 and 12 hours than I would just stick with 8.

FL_Reefer · Jun 14, 2014

I wish I could answer that. I have never ran mine for more the 5 hrs a day since I've had my tank up.

Aqua fire/medic · Jun 14, 2014

I've read in a couple different places that corals really only use the first 4-6 hours of light for photosynthesis...... I know ppl that run halides all day long but that is so that they can see and enjoy the tank. You could do the same, but don't think you will see increased growth from it.

alan.reef · Jun 14, 2014

Following

bknapp · Jun 14, 2014

I've got three halides and eight T5's over my 180 the T5 run for about 11 hours and the two outer halides run for 6 and the center halide runs for 4. The halides are all 250 watt DE 14K Pheonix.

Acro Crazy · Jun 14, 2014

Aqua fire/medic said:
I've read in a couple different places that corals really only use the first 4-6 hours of light for photosynthesis...... I know ppl that run halides all day long but that is so that they can see and enjoy the tank. You could do the same, but don't think you will see increased growth from it.

I would be really interested to get some links on that info, if that's true than that answers my question.
If you could post those that would be great.

Ostentum · Jun 14, 2014

I think the sweet spot for most people is around 6.5 hrs. I will try to find some of the studies that have been done in the past. Remember also that feeding and flow are just as if not more important then the light itself, not saying you can get by with PC with that philosophy, but still a huge factor in growth and coloration

trido · Jun 15, 2014

I used to run my 250 watt MH 14K bulbs for 10 hours a day for years. When I had 400 watters I backed them down to 8-9 hours but have always ran for 13 hours dawn to dusk.

bknapp · Jun 15, 2014

trido said:
I used to run my 250 watt MH 14K bulbs for 10 hours a day for years. When I had 400 watters I backed them down to 8-9 hours but have always ran for 13 hours dawn to dusk.

How was your growth rate? Any algae issues?

Acro Crazy · Jun 15, 2014

Ostentum said:
I think the sweet spot for most people is around 6.5 hrs. I will try to find some of the studies that have been done in the past. Remember also that feeding and flow are just as if not more important then the light itself, not saying you can get by with PC with that philosophy, but still a huge factor in growth and coloration

Sweet look forward to it! As for flow and feeding they are dialed in. I've got no complaints as far as coloration and PE. I'm strictly wondering if more MH hours equals extended growth.

jordan banks · Jun 15, 2014

I run mine 10 am to 8 pm. Ten hours during late spring and summer. As fall approaches I decrease photo period by 30 minutes until day light savings time hits and fall arrives I run them for eight hours a day. Then I run them from 9 to 5 during winter. I try my best to give them a natural light cycle. I have excellent growth rate with my halides. My tank is infested with coral.

Acro Crazy · Jun 15, 2014

Well I read this thread for way too long.

shorter photo period = faster growth - Reef Central Online Community

Then read this which was better.

Feature Article: A Different Look at Lighting: Effects of Prolonged Photoperiod, Spectral Quality, and Light Dosage ? Advanced Aquarist | Aquarist Magazine and Blog

I'm sticking with 8 hours of metal halide. And if I do feel like I want to try something I will follow the golden rule and change 1 thing at a time.

Aqua fire/medic · Jun 15, 2014

Acro Crazy said:
I would be really interested to get some links on that info, if that's true than that answers my question.
If you could post those that would be great.

I'll look today for sure..... It's been about a year.