tips on transitioning to MH frm T5?

[pascal32]

I've been looking and haven't found much. Lots on MH to T5, not so much on the other way around.

Tank is a 120gallon 2x4. mixed reef, SPS on top, LPS mid and down with mushrooms on the bottom. All kinds of stuff, euphilia, favias, fungia, clab, RBTA etc.

I'll be going from 8/10 T5s to two 250 watt 14K hamiltons in pendants on icecap ballasts. no supplementation for now.

current light schedule:

11:30 - total - 2xt5
11:45 - total - 4xT5
12:00-1:00 - total - 8xT5
1:00-3:00- total 10xT5s
3:00-8:00 - total - 8xT5
8:00-8:15 - total 4xT5
8:15-8:30 - total 2XT5s

total light cycle: 9 hours
8 hours of 8x with a 2 hour of 10 (all the way in the back, not sure how much they do)

I've never run MH so please help me with the obvious!

what height above water should i end up at?
how high should I start?
recommended light cycle?
should I screen for the first couple days?

From what I've read T5s are more intense, but dont have penetration. if that simplified explanation is accurate I'm putting a TON of light against my SPS on top which is why they are doing well, though the ones mid and down are not as good. so I'm worried about light shocking the lower half of the tank where all my LPS is.

I have a lot to loose, so I would prefer to do this gently and carefully.

thanks for the help!

quick FTS from a week or two ago (now holding two frag racks and a few more LPS:

 

[pascal32]

BTW - if someone can explain why the coraline on the glass stops in a near perfect line inches below the the water surface that would be cool

 

[Gary Majchrzak]

just to be safe

just to be safe

if screening isn't a hassle I'd reccommend it....

I'd start out with MH running 12 to 3. Ramp up slowly from there.
Halides create a "hot spot" directly under the lamp. Corals off center of this spot should be okay. Halides (lamps) should be 8 -10 " above water.

 

[pascal32]

if screening isn't a hassle I'd reccommend it....

I'd start out with MH running 12 to 3. Ramp up slowly from there.
Halides create a "hot spot" directly under the lamp. Corals off center of this spot should be okay. Halides (lamps) should be 8 -10 " above water.

no hassle at all, if it makes it easier on the life in the tank I'll make it happen.

Do you suggest starting right out at 8-12, or starting higher and working down?

 

[der_wille_zur_macht]

BTW - if someone can explain why the coraline on the glass stops in a near perfect line inches below the the water surface that would be cool

I bet the trim on the top edge of the tank is shading the glass above that point.

no hassle at all, if it makes it easier on the life in the tank I'll make it happen.

Do you suggest starting right out at 8-12, or starting higher and working down?

If you do multiple screens, no need to change height - mount at your chosen height, and start with several layers of screen on the tank. Remove a layer every few days.

Of course, you could do the opposite - forget the screen, and start with the lights 24" up, lowering them two or three inches every few days. Though from an "environmental impact" standpoint, seeing that the tank is right in your living room, the screening option is probably better. A pair of MH pendants two feet up are going to spill a lot of light into the room which will be a bit annoying.

 

[pascal32]

I bet the trim on the top edge of the tank is shading the glass above that point.



If you do multiple screens, no need to change height - mount at your chosen height, and start with several layers of screen on the tank. Remove a layer every few days.

Of course, you could do the opposite - forget the screen, and start with the lights 24" up, lowering them two or three inches every few days. Though from an "environmental impact" standpoint, seeing that the tank is right in your living room, the screening option is probably better. A pair of MH pendants two feet up are going to spill a lot of light into the room which will be a bit annoying.

cool. I picked up a set of non-metal window blinds in frames that fit the tank. I'll pick up another set!

thanks!

 

[pascal32]

First day with halides was interesting.

lights are up at 12" with 3 layers of screening under the light.

the light duration is set for 3 hours. I was going to remove once screen per day, then duration 1 hour per day to 8 hours - is that too quick?

tested last light and found out that the GFI breaker at the main panel goes everytime I plug them in. Fortunately there is a second line right next to the dedicated tank line so I moved over. lights tested fine, no issue.

set the timer on the reefleeper from 12-3. starting at 12 the reefkeeper reset every 15 minutes, e-mails galore on the phone. When my wife got home I had her plug the lights into the outlet directly and they stayed on, though the reefkeper reset quite a few times.

Called digital aquatics tech support (who answered in < 1 minute) - said the data cable is likely too close to the ballast. got home, sure enough 1" of separation. I'll have to clean up the cables and get things tucked away nicely.

all in a day of reefing

 

[pascal32]

cleaned up the wiring and got nice separation of the electrical lines and the bus cables - RKE is not longer resetting

I measured PAR today - the MH @ 12" without any screens 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 raising the lights 1.5" and ditching screens. photoperiod is 4 hours. one hour a week increase and 1.5" drop sound good?

hoping to have T5 supplement on-line this weekend

 

[Gravesj1s]

Curious, how much better was par measured to the bottom compared to the t-5?

 

[pascal32]

Curious, how much better was par measured to the bottom compared to the t-5?

why did you have to go there Steve? I didn't write anything down. I'll check it again tomorrow. it's a tough comparison since the par at the top isn't the same.

On the sand the PAR number was below original, though much closer than at the top (also down), so in relative terms it is quite the improvement.

If its OK with you I'd rather re-measure tomorrow instead of guess!