Transitioning from LED to MH

[EMeyer]

I think a shorter photoperiod but with high intensity will still shock coral....so I don't think that alone will work...I've had corals...all of a sudden not open up for weeks..and I realize after the fact..it's because I increased intensity too fast

It worked out fine. I started at 1 hr per day, increased it by 1 hour every 2 days til I hit my final 5 hours. (they get ~100 PAR of blue LEDs for about 10 hours, so the MH are just for the mid day high light period)

I also was uncertain if it would work

 

[EMeyer]

I went backwards. LED to T5’s to MH

I'm only a few weeks in, how do you like the switch long term?

 

[resortez]

Nice move. Curious to know what fixtures are you using, what brand bulbs & kelvins? Pics from f the tank? My best setup I have owned was a T5 & MH combo. My old living space had utilities included so I went all out on my tank. I had a retro fit fixture with an electronic ballasts running 250 radium 20k moguls, those produced a nice soft blue. The last bulbs I tried were ushios 22k & those produce a really strong blue hue & made everything pop, growth was amazing & that shimmer would put you in a trance. Best lighting I’ve ever owned.

 

[Bpb]

I'm only a few weeks in, how do you like the switch long term?

So far so good. I’m 10 months in. Intensity is stronger, and I keep some nutrients in the water, and maintain calcium and alkalinity through a calcium reactor, so the building blocks are all there, therefore growth has improved. I’ve had two large colonies topple over under their weight recently.

Heat hasn’t been a factor. I run a canopy which the t5’s completely “sealed off” the top of, as they covered the footprint exactly, the halide reflectors leave openings as vents. My temps have actually DROPPED about 1 degree going from 8x54 watt t5ho to 2x250 watt MH with 2-75 watt blue led strips run at 50%.

Truthfully. I care about acropora primarily. And we know acros do well under MH (of course they can thrive under any type, but just saying, they like MH, it’s easy). So I had zero concern about switching.

My primary reason though was I got the setup for free. 3-like new coralvue lumen bright pendants with 2-like new Hamilton m58 ballasts and 1 like new luxcore 250-400 watt ballast. I sold my sunpower for $250, as well as a couple acro packs and went and bought myself 15 bulbs to cover bulb changes for some years to come. Electricity is basically a wash, so it was just a convenient change to make. Anyone who is offered a quality metal halide setup would be foolish not to accept it unless you’re in a place with absurdly high electrical costs like on the west coast. I couldn’t imagine going out and spending $2000-3000 on lighting to replace what is working perfectly and essentially didn’t cost me anything. To save what? Maybe $10 a month on electricity?

 

[biecacka]

I went halides to leds.....and am already thinking of switching back. But I know I haven’t given the leds enough time(about 2 months)

Corey