Question on photoperiod and height of pendants

[Guy]

I changed the lighting on my 29 gallon from a 1 x 250 MH 12K sunburst to 2x175 12k sunburst. The light coverage is much better, but I am getting a bit more algae growth on the glass etc, which is understandable.

 

My question is about the photoperiod. I was originally running the 250MH for 12 hrs, which I thought was a bit long. So I felt it was advantageous to reduce the photoperiod to 10 hours with the new set up, as well as raise the pendants a bit higher. I now have them fairly high off of the water at about 12-13”. (The old set up was about 9” off the water.)

I made the changes because the corals seem to be doing better after the lights went out. By that I mean, they actually had better expansion after dark than when they where under the lights. I did acclimate the corals to the change over a 2 week period by lowering the pendant a bit every few days until it was at it’s current height.

 

Everything now seems to be doing well with the new set up, but my question is does anyone out there see any issues with the changes that may not appear until a few weeks down the road from the change.

 

Inhabitants:

 

I have all soft corals in the tank

2 Kenya tree corals

2 cabbage leaf corals. (Maybe the wrong name)

Mushrooms

Ricordia

Clove polyps

 

Thanks

Guy

[Guy]

I'll take no news as good news?

Up

 

Guy

[wenhamjj]

I am very new at this, but from what I have been reading, most soft corals dont like that much light. Your set up is more for the hard corals and maybe clams of some sort. IMO.

[Undertheradar]

Those 175s combined dont put out as much as that 250 did I bet (175s have dismal PAR/watt ratings)...but I can understand the whole coverage thing...although it has really just resulted in more glass coverage. I gotta say, I woulda left it prolly...maybe just swapped out the socket for an HQI instead of mugul....that wouyld have been more light. But FWIW, even at the same height, your corals are pretty much getting the same amount of light as they were before...so I would just leave it. Many experts claim that 6 hours a day is all the exposure that is needed for halides...more is just waste. Now, I wouldnt go that far, but for the most part with all my halides, I run 8 hours a day and all the SPS and clams are fine. Considering all you are doing is softies...6 hours a day would prolly be fine.

[MrKrispy]

I run my 250W DE about 7 hours over my 20L. Most everything seemed okay at 6 hours, but I have been adding sps and wanted to bump it up an hour. I have the mini pendant about 9-10 inches off the water.

 

Do the yellow fiji leathers like to be at the top of the tank with intense light? Maybe I misread that somewhere.

[Guy]

Thanks for the replies.

 

I wasn't aware that the intensity of 175's was that poor in comparison to other wattages. But my decision was based on the fact that I had 2-175 ballasts already. The HQI was an interesting suggestion which I never really considered.

 

MR Kripsy, I don't have a yellow fiji leather, I have a cabbage Leaf which is no where near as attractive as the Fiji, but I do know the cabbage I have is doing well high up in the tank if that helps.

 

One last question to clairify the suggestions of a shorter photoperiod under halides. Am I correct in assuming you are supplementing the lighting with Flourescent? My pendants are halide only and I would need to add lighting if I was to go that route.

 

 

PS- Things are still doing well with the shortened peiod of 10 hours.

Thanks

Guy

[Undertheradar]

All things considered, your corals should be fine even under just 6 or 7 hours a day...dont be so nervous...LOL.

 

Some of my reefs I suppliment with actinic...but I try not to...I try to just stick with higher wattage/output bulbs in the 15,000-20,000K range to allow me to get away w/o actinics.

[MrKrispy]

Guy, yah I just have a single 20k bulb, 7 hours a day.