transitioning from T5 to MH

blurry · Oct 7, 2010

Its official, I just moved to MH.

Old lighting schedule was 8 T5s 8 hours a day on the 120.

New lights are two 250 MH mounted at 12"

I have 3 screens over the tank and running 3 hours right now. what is the recomended for a rate of removing the screens and increasing duration?

I was thinking of removing 1 screen per day and then 1 hour per day increase after that - am i moving too fast?

thanks!

luke33 · Oct 7, 2010

Its tough to say what was more intense. What t5 fixture and what bulb's did you run over your tank and what mh fixture or pendent are you running with what bulb's and ballasts? Your t5's could have been more intense.

blurry · Oct 7, 2010

luke33 said:
Its tough to say what was more intense. What t5 fixture and what bulb's did you run over your tank and what mh fixture or pendent are you running with what bulb's and ballasts? Your t5's could have been more intense.

I was running (1) nova extreme 6X and (1) Nova Extereme 4x with only 2 bulbs for day (9th and 10th bulb run for two hours last 2 weeks to a moth) Bulbs were ATI Blue+ and Geissman middays with one KZ Fiji

The MH is two 250 watt 14K phoenix in a lumenMax 3 reflector driven by icecap ballasts

I used PAR meter (not sure when it was last calibrated) a while back which showed I was putting about 190 PAR mid and 270 at the top of my stack. I did start running the 9th and 10th light for 2 hours a day for the last two weeks to a month which bumps par about 90 in those two locations.

does that help?

mfinn · Oct 8, 2010

I would think if you added one more layer of screen, you could bump your light cycle back up to a full day.
Then just remove one layer every 4 days or so.

SaraB · Oct 8, 2010

I think you may be moving too fast by raising it in 1 hour per day increments. When I change out a MH bulb, I cut my photo period in half and then add an hour every 10 days. I'd rather be safer with less light than bleaching them with too much light.

blurry · Oct 8, 2010

I measured PAR today - the MH @ 12" is putting 80 to 60 par less to the corals. I did notice the penetration to the bottom of the tank is WAY better than the T5s

These bulbs are about 10 months old, so the output is likely 75% or so of original, that and i have some water turbulence.

I would prefer to get the screens off and increase from there. three screens cut PAR at the top to 90 so i took that off. Thinking of leaving the double on for one day, then single for 4 and then increasing duration from there per Sara's comment - thoughts?