Too close?

[bugj51]

How close is too close to have MH bulbs to the water?

I have some MH mogul reflectors. If I put them in the canopy I have, they will be about 6-8 inches off the water. It is a 30" tall tank.

[jcnkt_ellis]

I have 2 250MH bulbs mounted in the canopy on my 30" tank and I haven't had a problem with them. The two fans I have inside the canopy to cool the air works as well as when I was canopy-less and had the lights higher. As far as coral, the peak of my rocks are maybe halfway up the tank and the few lps and sps I have on top of the shelf is doing great and growing. The softies I have a quarter down the rocks and down to the sandbed are growing well too. Hope this helps.

[BBQHILLBILLY]

Very good info. I will be using MH with LEDs. Are you growing coral 30" or more down from MH? I was think of making a 1ft tall canopy to get away from splash and get more spread.
But I may have to goto 400W MH. lmk

[CoryDude]

Dude, 400 watts is a lot of heat inside a canopy. 250W with a good reflector will let you grow acros. I've got 250 w hqi about 10 inches above the water and I've got acros on the substrate.

[allan]

I think my lamps are about 18" off the surface, wish I could lower them. The 400 is even higher. Water still heats up and I've got a suspended canopy.

Actually, the room gets hot as well. If you can go 250, I would. I've not tried acros on my sand bed but I do have digitata growing into a little tree, I think its reaching for the light.

The 250s are standard pendants. The 400 has a lumen arc reflector. Much better.

[jcnkt_ellis]

Very good info. I will be using MH with LEDs. Are you growing coral 30" or more down from MH? I was think of making a 1ft tall canopy to get away from splash and get more spread.
But I may have to goto 400W MH. lmk

My MH are probably 8" above the water (just low enough for me to burn my arm if I'm not careful) and I have acan's growing on the sandbed.

[txav8r]

Mine are about 4" above the water. Never had a problem.

[LuckySingh]

which reflectors do u hve....
i am using three lumenbright lrg reflectors and they needed to be hung atleast 12 to 15 " for the better spread...mine r sitting on top of the canopy about 15" away from the water...i just switched all my lights to 400wtts and i can already tell the difference.....in general MH needs to be atleast 10" away from the water or it'll easy cook ur tank in no time if u dnt hve any chiller

[bugj51]

i have spider reflectors and 175w ballasts i bought from a member. looks like i should be ok in the canopy with the lower wattage. my rockwork goes up 3/4 ofthe tank.